8322 nl: misleading-indentation

[unleashed/tickless.git] / usr / src / uts / common / os / sunpm.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*
 * Copyright 2010 Nexenta Systems, Inc.  All rights reserved.
 */

/*
 * sunpm.c builds sunpm.o       "power management framework"
 *      kernel-resident power management code.  Implements power management
 *      policy
 *      Assumes: all backwards compat. device components wake up on &
 *               the pm_info pointer in dev_info is initially NULL
 *
 * PM - (device) Power Management
 *
 * Each device may have 0 or more components.  If a device has no components,
 * then it can't be power managed.  Each component has 2 or more
 * power states.
 *
 * "Backwards Compatible" (bc) devices:
 * There are two different types of devices from the point of view of this
 * code.  The original type, left over from the original PM implementation on
 * the voyager platform are known in this code as "backwards compatible"
 * devices (PM_ISBC(dip) returns true).
 * They are recognized by the pm code by the lack of a pm-components property
 * and a call made by the driver to pm_create_components(9F).
 * For these devices, component 0 is special, and represents the power state
 * of the device.  If component 0 is to be set to power level 0 (off), then
 * the framework must first call into the driver's detach(9E) routine with
 * DDI_PM_SUSPEND, to get the driver to save the hardware state of the device.
 * After setting component 0 from 0 to a non-zero power level, a call must be
 * made into the driver's attach(9E) routine with DDI_PM_RESUME.
 *
 * Currently, the only way to get a bc device power managed is via a set of
 * ioctls (PM_DIRECT_PM, PM_SET_CURRENT_POWER) issued to /dev/pm.
 *
 * For non-bc devices, the driver describes the components by exporting a
 * pm-components(9P) property that tells how many components there are,
 * tells what each component's power state values are, and provides human
 * readable strings (currently unused) for each component name and power state.
 * Devices which export pm-components(9P) are automatically power managed
 * whenever autopm is enabled (via PM_START_PM ioctl issued by pmconfig(1M)
 * after parsing power.conf(4)). The exception to this rule is that power
 * manageable CPU devices may be automatically managed independently of autopm
 * by either enabling or disabling (via PM_START_CPUPM and PM_STOP_CPUPM
 * ioctls) cpupm. If the CPU devices are not managed independently, then they
 * are managed by autopm. In either case, for automatically power managed
 * devices, all components are considered independent of each other, and it is
 * up to the driver to decide when a transition requires saving or restoring
 * hardware state.
 *
 * Each device component also has a threshold time associated with each power
 * transition (see power.conf(4)), and a busy/idle state maintained by the
 * driver calling pm_idle_component(9F) and pm_busy_component(9F).
 * Components are created idle.
 *
 * The PM framework provides several functions:
 * -implement PM policy as described in power.conf(4)
 *  Policy is set by pmconfig(1M) issuing pm ioctls based on power.conf(4).
 *  Policies consist of:
 *    -set threshold values (defaults if none provided by pmconfig)
 *    -set dependencies among devices
 *    -enable/disable autopm
 *    -enable/disable cpupm
 *    -turn down idle components based on thresholds (if autopm or cpupm is
 *     enabled) (aka scanning)
 *    -maintain power states based on dependencies among devices
 *    -upon request, or when the frame buffer powers off, attempt to turn off
 *     all components that are idle or become idle over the next (10 sec)
 *     period in an attempt to get down to an EnergyStar compliant state
 *    -prevent powering off of a device which exported the
 *     pm-no-involuntary-power-cycles property without active involvement of
 *     the device's driver (so no removing power when the device driver is
 *     not attached)
 * -provide a mechanism for a device driver to request that a device's component
 *  be brought back to the power level necessary for the use of the device
 * -allow a process to directly control the power levels of device components
 *  (via ioctls issued to /dev/pm--see usr/src/uts/common/io/pm.c)
 * -ensure that the console frame buffer is powered up before being referenced
 *  via prom_printf() or other prom calls that might generate console output
 * -maintain implicit dependencies (e.g. parent must be powered up if child is)
 * -provide "backwards compatible" behavior for devices without pm-components
 *  property
 *
 * Scanning:
 * Whenever autopm or cpupm  is enabled, the framework attempts to bring each
 * component of each managed device to its lowest power based on the threshold
 * of idleness associated with each transition and the busy/idle state of the
 * component.
 *
 * The actual work of this is done by pm_scan_dev(), which cycles through each
 * component of a device, checking its idleness against its current threshold,
 * and calling pm_set_power() as appropriate to change the power level.
 * This function also indicates when it would next be profitable to scan the
 * device again, and a new scan is scheduled after that time.
 *
 * Dependencies:
 * It is possible to establish a dependency between the power states of two
 * otherwise unrelated devices.  This is currently done to ensure that the
 * cdrom is always up whenever the console framebuffer is up, so that the user
 * can insert a cdrom and see a popup as a result.
 *
 * The dependency terminology used in power.conf(4) is not easy to understand,
 * so we've adopted a different terminology in the implementation.  We write
 * of a "keeps up" and a "kept up" device.  A relationship can be established
 * where one device keeps up another.  That means that if the keepsup device
 * has any component that is at a non-zero power level, all components of the
 * "kept up" device must be brought to full power.  This relationship is
 * asynchronous.  When the keeping device is powered up, a request is queued
 * to a worker thread to bring up the kept device.  The caller does not wait.
 * Scan will not turn down a kept up device.
 *
 * Direct PM:
 * A device may be directly power managed by a process.  If a device is
 * directly pm'd, then it will not be scanned, and dependencies will not be
 * enforced.  * If a directly pm'd device's driver requests a power change (via
 * pm_raise_power(9F)), then the request is blocked and notification is sent
 * to the controlling process, which must issue the requested power change for
 * the driver to proceed.
 *
 */

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/callb.h>          /* callback registration during CPR */
#include <sys/conf.h>           /* driver flags and functions */
#include <sys/open.h>           /* OTYP_CHR definition */
#include <sys/stat.h>           /* S_IFCHR definition */
#include <sys/pathname.h>       /* name -> dev_info xlation */
#include <sys/ddi_impldefs.h>   /* dev_info node fields */
#include <sys/kmem.h>           /* memory alloc stuff */
#include <sys/debug.h>
#include <sys/archsystm.h>
#include <sys/pm.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/sunndi.h>
#include <sys/sunpm.h>
#include <sys/epm.h>
#include <sys/vfs.h>
#include <sys/mode.h>
#include <sys/mkdev.h>
#include <sys/promif.h>
#include <sys/consdev.h>
#include <sys/esunddi.h>
#include <sys/modctl.h>
#include <sys/fs/ufs_fs.h>
#include <sys/note.h>
#include <sys/taskq.h>
#include <sys/bootconf.h>
#include <sys/reboot.h>
#include <sys/spl.h>
#include <sys/disp.h>
#include <sys/sobject.h>
#include <sys/sunmdi.h>
#include <sys/systm.h>
#include <sys/cpuvar.h>
#include <sys/cyclic.h>
#include <sys/uadmin.h>
#include <sys/srn.h>


/*
 * PM LOCKING
 *      The list of locks:
 * Global pm mutex locks.
 *
 * pm_scan_lock:
 *              It protects the timeout id of the scan thread, and the value
 *              of autopm_enabled and cpupm.  This lock is not held
 *              concurrently with any other PM locks.
 *
 * pm_clone_lock:       Protects the clone list and count of poll events
 *              pending for the pm driver.
 *              Lock ordering:
 *                      pm_clone_lock -> pm_pscc_interest_rwlock,
 *                      pm_clone_lock -> pm_pscc_direct_rwlock.
 *
 * pm_rsvp_lock:
 *              Used to synchronize the data structures used for processes
 *              to rendezvous with state change information when doing
 *              direct PM.
 *              Lock ordering:
 *                      pm_rsvp_lock -> pm_pscc_interest_rwlock,
 *                      pm_rsvp_lock -> pm_pscc_direct_rwlock,
 *                      pm_rsvp_lock -> pm_clone_lock.
 *
 * ppm_lock:    protects the list of registered ppm drivers
 *              Lock ordering:
 *                      ppm_lock -> ppm driver unit_lock
 *
 * pm_compcnt_lock:
 *              Protects count of components that are not at their lowest
 *              power level.
 *              Lock ordering:
 *                      pm_compcnt_lock -> ppm_lock.
 *
 * pm_dep_thread_lock:
 *              Protects work list for pm_dep_thread.  Not taken concurrently
 *              with any other pm lock.
 *
 * pm_remdrv_lock:
 *              Serializes the operation of removing noinvol data structure
 *              entries for a branch of the tree when a driver has been
 *              removed from the system (modctl_rem_major).
 *              Lock ordering:
 *                      pm_remdrv_lock -> pm_noinvol_rwlock.
 *
 * pm_cfb_lock: (High level spin lock)
 *              Protects the count of how many components of the console
 *              frame buffer are off (so we know if we have to bring up the
 *              console as a result of a prom_printf, etc.
 *              No other locks are taken while holding this lock.
 *
 * pm_loan_lock:
 *              Protects the lock_loan list.  List is used to record that one
 *              thread has acquired a power lock but has launched another thread
 *              to complete its processing.  An entry in the list indicates that
 *              the worker thread can borrow the lock held by the other thread,
 *              which must block on the completion of the worker.  Use is
 *              specific to module loading.
 *              No other locks are taken while holding this lock.
 *
 * Global PM rwlocks
 *
 * pm_thresh_rwlock:
 *              Protects the list of thresholds recorded for future use (when
 *              devices attach).
 *              Lock ordering:
 *                      pm_thresh_rwlock -> devi_pm_lock
 *
 * pm_noinvol_rwlock:
 *              Protects list of detached nodes that had noinvol registered.
 *              No other PM locks are taken while holding pm_noinvol_rwlock.
 *
 * pm_pscc_direct_rwlock:
 *              Protects the list that maps devices being directly power
 *              managed to the processes that manage them.
 *              Lock ordering:
 *                      pm_pscc_direct_rwlock -> psce_lock
 *
 * pm_pscc_interest_rwlock;
 *              Protects the list that maps state change events to processes
 *              that want to know about them.
 *              Lock ordering:
 *                      pm_pscc_interest_rwlock -> psce_lock
 *
 * per-dip locks:
 *
 * Each node has these per-dip locks, which are only used if the device is
 * a candidate for power management (e.g. has pm components)
 *
 * devi_pm_lock:
 *              Protects all power management state of the node except for
 *              power level, which is protected by ndi_devi_enter().
 *              Encapsulated in macros PM_LOCK_DIP()/PM_UNLOCK_DIP().
 *              Lock ordering:
 *                      devi_pm_lock -> pm_rsvp_lock,
 *                      devi_pm_lock -> pm_dep_thread_lock,
 *                      devi_pm_lock -> pm_noinvol_rwlock,
 *                      devi_pm_lock -> power lock
 *
 * power lock (ndi_devi_enter()):
 *              Since changing power level is possibly a slow operation (30
 *              seconds to spin up a disk drive), this is locked separately.
 *              Since a call into the driver to change the power level of one
 *              component may result in a call back into the framework to change
 *              the power level of another, this lock allows re-entrancy by
 *              the same thread (ndi_devi_enter is used for this because
 *              the USB framework uses ndi_devi_enter in its power entry point,
 *              and use of any other lock would produce a deadlock.
 *
 * devi_pm_busy_lock:
 *              This lock protects the integrity of the busy count.  It is
 *              only taken by pm_busy_component() and pm_idle_component and
 *              some code that adjust the busy time after the timer gets set
 *              up or after a CPR operation.  It is per-dip to keep from
 *              single-threading all the disk drivers on a system.
 *              It could be per component instead, but most devices have
 *              only one component.
 *              No other PM locks are taken while holding this lock.
 *
 */

static int stdout_is_framebuffer;
static kmutex_t e_pm_power_lock;
static kmutex_t pm_loan_lock;
kmutex_t        pm_scan_lock;
callb_id_t      pm_cpr_cb_id;
callb_id_t      pm_panic_cb_id;
callb_id_t      pm_halt_cb_id;
int             pm_comps_notlowest;     /* no. of comps not at lowest power */
int             pm_powering_down;       /* cpr is source of DDI_SUSPEND calls */

clock_t pm_id_ticks = 5;        /* ticks to wait before scan during idle-down */
clock_t pm_default_min_scan = PM_DEFAULT_MIN_SCAN;
clock_t pm_cpu_min_scan = PM_CPU_MIN_SCAN;

#define PM_MIN_SCAN(dip)        (PM_ISCPU(dip) ? pm_cpu_min_scan : \
                                    pm_default_min_scan)

static int pm_busop_set_power(dev_info_t *,
    void *, pm_bus_power_op_t, void *, void *);
static int pm_busop_match_request(dev_info_t *, void *);
static int pm_all_to_normal_nexus(dev_info_t *, pm_canblock_t);
static void e_pm_set_max_power(dev_info_t *, int, int);
static int e_pm_get_max_power(dev_info_t *, int);

/*
 * Dependency Processing is done thru a seperate thread.
 */
kmutex_t        pm_dep_thread_lock;
kcondvar_t      pm_dep_thread_cv;
pm_dep_wk_t     *pm_dep_thread_workq = NULL;
pm_dep_wk_t     *pm_dep_thread_tail = NULL;

/*
 * Autopm  must be turned on by a PM_START_PM ioctl, so we don't end up
 * power managing things in single user mode that have been suppressed via
 * power.conf entries.  Protected by pm_scan_lock.
 */
int             autopm_enabled;

/*
 * cpupm is turned on and off, by the PM_START_CPUPM and PM_STOP_CPUPM ioctls,
 * to define the power management behavior of CPU devices separate from
 * autopm. Protected by pm_scan_lock.
 */
pm_cpupm_t      cpupm = PM_CPUPM_NOTSET;

/*
 * Defines the default mode of operation for CPU power management,
 * either the polling implementation, or the event based dispatcher driven
 * implementation.
 */
pm_cpupm_t      cpupm_default_mode = PM_CPUPM_EVENT;

/*
 * AutoS3 depends on autopm being enabled, and must be enabled by
 * PM_START_AUTOS3 command.
 */
int             autoS3_enabled;

#if !defined(__sparc)
/*
 * on sparc these live in fillsysinfo.c
 *
 * If this variable is non-zero, cpr should return "not supported" when
 * it is queried even though it would normally be supported on this platform.
 */
int cpr_supported_override;

/*
 * Some platforms may need to support CPR even in the absence of
 * having the correct platform id information.  If this
 * variable is non-zero, cpr should proceed even in the absence
 * of otherwise being qualified.
 */
int cpr_platform_enable = 0;

#endif

/*
 * pm_S3_enabled indicates that we believe the platform can support S3,
 * which we get from pmconfig(1M)
 */
int             pm_S3_enabled;

/*
 * This flag is true while processes are stopped for a checkpoint/resume.
 * Controlling processes of direct pm'd devices are not available to
 * participate in power level changes, so we bypass them when this is set.
 */
static int      pm_processes_stopped;

#ifdef  DEBUG

/*
 * see common/sys/epm.h for PMD_* values
 */

uint_t          pm_debug = 0;

/*
 * If pm_divertdebug is set, then no prom_printf calls will be made by
 * PMD(), which will prevent debug output from bringing up the console
 * frame buffer.  Clearing this variable before setting pm_debug will result
 * in PMD output going to the console.
 *
 * pm_divertdebug is incremented in pm_set_power() if dip == cfb_dip to avoid
 * deadlocks and decremented at the end of pm_set_power()
 */
uint_t          pm_divertdebug = 1;
volatile uint_t pm_debug_to_console = 0;
kmutex_t        pm_debug_lock;          /* protects pm_divertdebug */

void prdeps(char *);
#endif

/* Globals */

/*
 * List of recorded thresholds and dependencies
 */
pm_thresh_rec_t *pm_thresh_head;
krwlock_t pm_thresh_rwlock;

pm_pdr_t *pm_dep_head;
static int pm_unresolved_deps = 0;
static int pm_prop_deps = 0;

/*
 * List of devices that exported no-involuntary-power-cycles property
 */
pm_noinvol_t *pm_noinvol_head;

/*
 * Locks used in noinvol processing
 */
krwlock_t pm_noinvol_rwlock;
kmutex_t pm_remdrv_lock;

int pm_default_idle_threshold = PM_DEFAULT_SYS_IDLENESS;
int pm_system_idle_threshold;
int pm_cpu_idle_threshold;

/*
 * By default nexus has 0 threshold, and depends on its children to keep it up
 */
int pm_default_nexus_threshold = 0;

/*
 * Data structures shared with common/io/pm.c
 */
kmutex_t        pm_clone_lock;
kcondvar_t      pm_clones_cv[PM_MAX_CLONE];
uint_t          pm_poll_cnt[PM_MAX_CLONE];      /* count of events for poll */
unsigned char   pm_interest[PM_MAX_CLONE];
struct pollhead pm_pollhead;

/*
 * Data structures shared with common/io/srn.c
 */
kmutex_t        srn_clone_lock;         /* protects srn_signal, srn_inuse */
void (*srn_signal)(int type, int event);
int srn_inuse;                          /* stop srn detach */

extern int      hz;
extern char     *platform_module_list[];

/*
 * Wrappers for use in ddi_walk_devs
 */

static int              pm_set_dev_thr_walk(dev_info_t *, void *);
static int              pm_restore_direct_lvl_walk(dev_info_t *, void *);
static int              pm_save_direct_lvl_walk(dev_info_t *, void *);
static int              pm_discard_dep_walk(dev_info_t *, void *);
#ifdef DEBUG
static int              pm_desc_pwrchk_walk(dev_info_t *, void *);
#endif

/*
 * Routines for managing noinvol devices
 */
int                     pm_noinvol_update(int, int, int, char *, dev_info_t *);
void                    pm_noinvol_update_node(dev_info_t *,
                            pm_bp_noinvol_t *req);

kmutex_t pm_rsvp_lock;
kmutex_t pm_compcnt_lock;
krwlock_t pm_pscc_direct_rwlock;
krwlock_t pm_pscc_interest_rwlock;

#define PSC_INTEREST    0       /* belongs to interest psc list */
#define PSC_DIRECT      1       /* belongs to direct psc list */

pscc_t *pm_pscc_interest;
pscc_t *pm_pscc_direct;

#define PM_MAJOR(dip) ddi_driver_major(dip)
#define PM_IS_NEXUS(dip) ((PM_MAJOR(dip) == DDI_MAJOR_T_NONE) ? 0 : \
        NEXUS_DRV(devopsp[PM_MAJOR(dip)]))
#define POWERING_ON(old, new) ((old) == 0 && (new) != 0)
#define POWERING_OFF(old, new) ((old) != 0 && (new) == 0)

#define PM_INCR_NOTLOWEST(dip) {                                        \
        mutex_enter(&pm_compcnt_lock);                                  \
        if (!PM_IS_NEXUS(dip) ||                                        \
            (DEVI(dip)->devi_pm_flags & (PMC_DEV_THRESH|PMC_COMP_THRESH))) {\
                if (pm_comps_notlowest == 0)                            \
                        pm_ppm_notify_all_lowest(dip, PM_NOT_ALL_LOWEST);\
                pm_comps_notlowest++;                                   \
                PMD(PMD_LEVEL, ("%s: %s@%s(%s#%d) incr notlowest->%d\n",\
                    pmf, PM_DEVICE(dip), pm_comps_notlowest))           \
        }                                                               \
        mutex_exit(&pm_compcnt_lock);                                   \
}
#define PM_DECR_NOTLOWEST(dip) {                                        \
        mutex_enter(&pm_compcnt_lock);                                  \
        if (!PM_IS_NEXUS(dip) ||                                        \
            (DEVI(dip)->devi_pm_flags & (PMC_DEV_THRESH|PMC_COMP_THRESH))) {\
                ASSERT(pm_comps_notlowest);                             \
                pm_comps_notlowest--;                                   \
                PMD(PMD_LEVEL, ("%s: %s@%s(%s#%d) decr notlowest to "   \
                            "%d\n", pmf, PM_DEVICE(dip), pm_comps_notlowest))\
                if (pm_comps_notlowest == 0)                            \
                        pm_ppm_notify_all_lowest(dip, PM_ALL_LOWEST);   \
        }                                                               \
        mutex_exit(&pm_compcnt_lock);                                   \
}

/*
 * console frame-buffer power-management is not enabled when
 * debugging services are present.  to override, set pm_cfb_override
 * to non-zero.
 */
uint_t pm_cfb_comps_off = 0;    /* PM_LEVEL_UNKNOWN is considered on */
kmutex_t pm_cfb_lock;
int pm_cfb_enabled = 1;         /* non-zero allows pm of console frame buffer */
#ifdef DEBUG
int pm_cfb_override = 1;        /* non-zero allows pm of cfb with debuggers */
#else
int pm_cfb_override = 0;        /* non-zero allows pm of cfb with debuggers */
#endif

static dev_info_t *cfb_dip = 0;
static dev_info_t *cfb_dip_detaching = 0;
uint_t cfb_inuse = 0;
static ddi_softintr_t pm_soft_id;
static boolean_t pm_soft_pending;
int     pm_scans_disabled = 0;

/*
 * A structure to record the fact that one thread has borrowed a lock held
 * by another thread.  The context requires that the lender block on the
 * completion of the borrower.
 */
typedef struct lock_loan {
        struct lock_loan        *pmlk_next;
        kthread_t               *pmlk_borrower;
        kthread_t               *pmlk_lender;
        dev_info_t              *pmlk_dip;
} lock_loan_t;
static lock_loan_t lock_loan_head;      /* list head is a dummy element */

#ifdef  DEBUG
#ifdef  PMDDEBUG
#define PMD_FUNC(func, name)    char *(func) = (name);
#else   /* !PMDDEBUG */
#define PMD_FUNC(func, name)
#endif  /* PMDDEBUG */
#else   /* !DEBUG */
#define PMD_FUNC(func, name)
#endif  /* DEBUG */


/*
 * Must be called before first device (including pseudo) attach
 */
void
pm_init_locks(void)
{
        mutex_init(&pm_scan_lock, NULL, MUTEX_DRIVER, NULL);
        mutex_init(&pm_rsvp_lock, NULL, MUTEX_DRIVER, NULL);
        mutex_init(&pm_compcnt_lock, NULL, MUTEX_DRIVER, NULL);
        mutex_init(&pm_dep_thread_lock, NULL, MUTEX_DRIVER, NULL);
        mutex_init(&pm_remdrv_lock, NULL, MUTEX_DRIVER, NULL);
        mutex_init(&pm_loan_lock, NULL, MUTEX_DRIVER, NULL);
        rw_init(&pm_thresh_rwlock, NULL, RW_DEFAULT, NULL);
        rw_init(&pm_noinvol_rwlock, NULL, RW_DEFAULT, NULL);
        cv_init(&pm_dep_thread_cv, NULL, CV_DEFAULT, NULL);
}

static int pm_reset_timestamps(dev_info_t *, void *);

static boolean_t
pm_cpr_callb(void *arg, int code)
{
        _NOTE(ARGUNUSED(arg))
        static int auto_save;
        static pm_cpupm_t cpupm_save;

        switch (code) {
        case CB_CODE_CPR_CHKPT:
                /*
                 * Cancel scan or wait for scan in progress to finish
                 * Other threads may be trying to restart the scan, so we
                 * have to keep at it unil it sticks
                 */
                mutex_enter(&pm_scan_lock);
                ASSERT(!pm_scans_disabled);
                pm_scans_disabled = 1;
                auto_save = autopm_enabled;
                autopm_enabled = 0;
                cpupm_save = cpupm;
                cpupm = PM_CPUPM_NOTSET;
                mutex_exit(&pm_scan_lock);
                ddi_walk_devs(ddi_root_node(), pm_scan_stop_walk, NULL);
                break;

        case CB_CODE_CPR_RESUME:
                ASSERT(!autopm_enabled);
                ASSERT(cpupm == PM_CPUPM_NOTSET);
                ASSERT(pm_scans_disabled);
                pm_scans_disabled = 0;
                /*
                 * Call pm_reset_timestamps to reset timestamps of each
                 * device to the time when the system is resumed so that their
                 * idleness can be re-calculated. That's to avoid devices from
                 * being powered down right after resume if the system was in
                 * suspended mode long enough.
                 */
                ddi_walk_devs(ddi_root_node(), pm_reset_timestamps, NULL);

                autopm_enabled = auto_save;
                cpupm = cpupm_save;
                /*
                 * If there is any auto-pm device, get the scanning
                 * going. Otherwise don't bother.
                 */
                ddi_walk_devs(ddi_root_node(), pm_rescan_walk, NULL);
                break;
        }
        return (B_TRUE);
}

/*
 * This callback routine is called when there is a system panic.  This function
 * exists for prototype matching.
 */
static boolean_t
pm_panic_callb(void *arg, int code)
{
        _NOTE(ARGUNUSED(arg, code))
        void pm_cfb_check_and_powerup(void);
        PMD(PMD_CFB, ("pm_panic_callb\n"))
        pm_cfb_check_and_powerup();
        return (B_TRUE);
}

static boolean_t
pm_halt_callb(void *arg, int code)
{
        _NOTE(ARGUNUSED(arg, code))
        return (B_TRUE);
}

static void pm_dep_thread(void);

/*
 * This needs to be called after the root and platform drivers are loaded
 * and be single-threaded with respect to driver attach/detach
 */
void
pm_init(void)
{
        PMD_FUNC(pmf, "pm_init")
        char **mod;
        extern pri_t minclsyspri;

        pm_comps_notlowest = 0;
        pm_system_idle_threshold = pm_default_idle_threshold;
        pm_cpu_idle_threshold = 0;

        pm_cpr_cb_id = callb_add(pm_cpr_callb, (void *)NULL,
            CB_CL_CPR_PM, "pm_cpr");
        pm_panic_cb_id = callb_add(pm_panic_callb, (void *)NULL,
            CB_CL_PANIC, "pm_panic");
        pm_halt_cb_id = callb_add(pm_halt_callb, (void *)NULL,
            CB_CL_HALT, "pm_halt");

        /*
         * Create a thread to do dependency processing.
         */
        (void) thread_create(NULL, 0, (void (*)())pm_dep_thread, NULL, 0, &p0,
            TS_RUN, minclsyspri);

        /*
         * loadrootmodules already loaded these ppm drivers, now get them
         * attached so they can claim the root drivers as they attach
         */
        for (mod = platform_module_list; *mod; mod++) {
                if (i_ddi_attach_hw_nodes(*mod) != DDI_SUCCESS) {
                        cmn_err(CE_WARN, "!cannot load platform pm driver %s\n",
                            *mod);
                } else {
                        PMD(PMD_DHR, ("%s: %s (%s)\n", pmf, *mod,
                            ddi_major_to_name(ddi_name_to_major(*mod))))
                }
        }
}

/*
 * pm_scan_init - create pm scan data structure.  Called (if autopm or cpupm
 * enabled) when device becomes power managed or after a failed detach and
 * when autopm is started via PM_START_PM or PM_START_CPUPM ioctls, and after
 * a CPR resume to get all the devices scanning again.
 */
void
pm_scan_init(dev_info_t *dip)
{
        PMD_FUNC(pmf, "scan_init")
        pm_scan_t       *scanp;

        ASSERT(!PM_ISBC(dip));

        PM_LOCK_DIP(dip);
        scanp = PM_GET_PM_SCAN(dip);
        if (!scanp) {
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): create scan data\n",
                    pmf, PM_DEVICE(dip)))
                scanp =  kmem_zalloc(sizeof (pm_scan_t), KM_SLEEP);
                DEVI(dip)->devi_pm_scan = scanp;
        } else if (scanp->ps_scan_flags & PM_SCAN_STOP) {
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): "
                    "clear PM_SCAN_STOP flag\n", pmf, PM_DEVICE(dip)))
                scanp->ps_scan_flags &= ~PM_SCAN_STOP;
        }
        PM_UNLOCK_DIP(dip);
}

/*
 * pm_scan_fini - remove pm scan data structure when stopping pm on the device
 */
void
pm_scan_fini(dev_info_t *dip)
{
        PMD_FUNC(pmf, "scan_fini")
        pm_scan_t       *scanp;

        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        ASSERT(!PM_ISBC(dip));
        PM_LOCK_DIP(dip);
        scanp = PM_GET_PM_SCAN(dip);
        if (!scanp) {
                PM_UNLOCK_DIP(dip);
                return;
        }

        ASSERT(!scanp->ps_scan_id && !(scanp->ps_scan_flags &
            (PM_SCANNING | PM_SCAN_DISPATCHED | PM_SCAN_AGAIN)));

        kmem_free(scanp, sizeof (pm_scan_t));
        DEVI(dip)->devi_pm_scan = NULL;
        PM_UNLOCK_DIP(dip);
}

/*
 * Given a pointer to a component struct, return the current power level
 * (struct contains index unless it is a continuous level).
 * Located here in hopes of getting both this and dev_is_needed into the
 * cache together
 */
static int
cur_power(pm_component_t *cp)
{
        if (cp->pmc_cur_pwr == PM_LEVEL_UNKNOWN)
                return (cp->pmc_cur_pwr);

        return (cp->pmc_comp.pmc_lvals[cp->pmc_cur_pwr]);
}

static char *
pm_decode_direction(int direction)
{
        switch (direction) {
        case PM_LEVEL_UPONLY:
                return ("up");

        case PM_LEVEL_EXACT:
                return ("exact");

        case PM_LEVEL_DOWNONLY:
                return ("down");

        default:
                return ("INVALID DIRECTION");
        }
}

char *
pm_decode_op(pm_bus_power_op_t op)
{
        switch (op) {
        case BUS_POWER_CHILD_PWRCHG:
                return ("CHILD_PWRCHG");
        case BUS_POWER_NEXUS_PWRUP:
                return ("NEXUS_PWRUP");
        case BUS_POWER_PRE_NOTIFICATION:
                return ("PRE_NOTIFICATION");
        case BUS_POWER_POST_NOTIFICATION:
                return ("POST_NOTIFICATION");
        case BUS_POWER_HAS_CHANGED:
                return ("HAS_CHANGED");
        case BUS_POWER_NOINVOL:
                return ("NOINVOL");
        default:
                return ("UNKNOWN OP");
        }
}

/*
 * Returns true if level is a possible (valid) power level for component
 */
int
e_pm_valid_power(dev_info_t *dip, int cmpt, int level)
{
        PMD_FUNC(pmf, "e_pm_valid_power")
        pm_component_t *cp = PM_CP(dip, cmpt);
        int i;
        int *ip = cp->pmc_comp.pmc_lvals;
        int limit = cp->pmc_comp.pmc_numlevels;

        if (level < 0)
                return (0);
        for (i = 0; i < limit; i++) {
                if (level == *ip++)
                        return (1);
        }
#ifdef DEBUG
        if (pm_debug & PMD_FAIL) {
                ip = cp->pmc_comp.pmc_lvals;

                for (i = 0; i < limit; i++)
                        PMD(PMD_FAIL, ("%s: index=%d, level=%d\n",
                            pmf, i, *ip++))
        }
#endif
        return (0);
}

static int pm_start(dev_info_t *dip);
/*
 * Returns true if device is pm'd (after calling pm_start if need be)
 */
int
e_pm_valid_info(dev_info_t *dip, pm_info_t **infop)
{
        pm_info_t *info;

        /*
         * Check if the device is power managed if not.
         * To make the common case (device is power managed already)
         * fast, we check without the lock.  If device is not already
         * power managed, then we take the lock and the long route through
         * go get it managed.  Devices never go unmanaged until they
         * detach.
         */
        info = PM_GET_PM_INFO(dip);
        if (!info) {
                if (!DEVI_IS_ATTACHING(dip)) {
                        return (0);
                }
                if (pm_start(dip) != DDI_SUCCESS) {
                        return (0);
                }
                info = PM_GET_PM_INFO(dip);
        }
        ASSERT(info);
        if (infop != NULL)
                *infop = info;
        return (1);
}

int
e_pm_valid_comp(dev_info_t *dip, int cmpt, pm_component_t **cpp)
{
        if (cmpt >= 0 && cmpt < PM_NUMCMPTS(dip)) {
                if (cpp != NULL)
                        *cpp = PM_CP(dip, cmpt);
                return (1);
        } else {
                return (0);
        }
}

/*
 * Internal guts of ddi_dev_is_needed and pm_raise/lower_power
 */
static int
dev_is_needed(dev_info_t *dip, int cmpt, int level, int direction)
{
        PMD_FUNC(pmf, "din")
        pm_component_t *cp;
        char *pathbuf;
        int result;

        ASSERT(direction == PM_LEVEL_UPONLY || direction == PM_LEVEL_DOWNONLY);
        if (!e_pm_valid_info(dip, NULL) || !e_pm_valid_comp(dip, cmpt, &cp) ||
            !e_pm_valid_power(dip, cmpt, level))
                return (DDI_FAILURE);

        PMD(PMD_DIN, ("%s: %s@%s(%s#%d) cmpt=%d, dir=%s, new=%d, cur=%d\n",
            pmf, PM_DEVICE(dip), cmpt, pm_decode_direction(direction),
            level, cur_power(cp)))

        if (pm_set_power(dip, cmpt, level,  direction,
            PM_CANBLOCK_BLOCK, 0, &result) != DDI_SUCCESS) {
                if (direction == PM_LEVEL_UPONLY) {
                        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
                        (void) ddi_pathname(dip, pathbuf);
                        cmn_err(CE_WARN, "Device %s failed to power up.",
                            pathbuf);
                        kmem_free(pathbuf, MAXPATHLEN);
                }
                PMD(PMD_DIN | PMD_FAIL, ("%s: %s@%s(%s#%d) [%d] %s->%d failed, "
                    "errno %d\n", pmf, PM_DEVICE(dip), cmpt,
                    pm_decode_direction(direction), level, result))
                return (DDI_FAILURE);
        }

        PMD(PMD_RESCAN | PMD_DIN, ("%s: pm_rescan %s@%s(%s#%d)\n", pmf,
            PM_DEVICE(dip)))
        pm_rescan(dip);
        return (DDI_SUCCESS);
}

/*
 * We can get multiple pm_rescan() threads, if one of them discovers
 * that no scan is running at the moment, it kicks it into action.
 * Otherwise, it tells the current scanning thread to scan again when
 * it is done by asserting the PM_SCAN_AGAIN flag. The PM_SCANNING and
 * PM_SCAN_AGAIN flags are used to regulate scan, to make sure only one
 * thread at a time runs the pm_scan_dev() code.
 */
void
pm_rescan(void *arg)
{
        PMD_FUNC(pmf, "rescan")
        dev_info_t      *dip = (dev_info_t *)arg;
        pm_info_t       *info;
        pm_scan_t       *scanp;
        timeout_id_t    scanid;

        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        PM_LOCK_DIP(dip);
        info = PM_GET_PM_INFO(dip);
        scanp = PM_GET_PM_SCAN(dip);
        if (pm_scans_disabled || !PM_SCANABLE(dip) || !info || !scanp ||
            (scanp->ps_scan_flags & PM_SCAN_STOP)) {
                PM_UNLOCK_DIP(dip);
                return;
        }
        if (scanp->ps_scan_flags & PM_SCANNING) {
                scanp->ps_scan_flags |= PM_SCAN_AGAIN;
                PM_UNLOCK_DIP(dip);
                return;
        } else if (scanp->ps_scan_id) {
                scanid = scanp->ps_scan_id;
                scanp->ps_scan_id = 0;
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): cancel timeout scanid %lx\n",
                    pmf, PM_DEVICE(dip), (ulong_t)scanid))
                PM_UNLOCK_DIP(dip);
                (void) untimeout(scanid);
                PM_LOCK_DIP(dip);
        }

        /*
         * Dispatching pm_scan during attach time is risky due to the fact that
         * attach might soon fail and dip dissolved, and panic may happen while
         * attempting to stop scan. So schedule a pm_rescan instead.
         * (Note that if either of the first two terms are true, taskq_dispatch
         * will not be invoked).
         *
         * Multiple pm_scan dispatching is unecessary and costly to keep track
         * of. The PM_SCAN_DISPATCHED flag is used between pm_rescan and pm_scan
         * to regulate the dispatching.
         *
         * Scan is stopped before the device is detached (in pm_detaching())
         * but it may get re-started during the post_detach processing if the
         * driver fails to detach.
         */
        if (DEVI_IS_ATTACHING(dip) ||
            (scanp->ps_scan_flags & PM_SCAN_DISPATCHED) ||
            !taskq_dispatch(system_taskq, pm_scan, (void *)dip, TQ_NOSLEEP)) {
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): attaching, pm_scan already "
                    "dispatched or dispatching failed\n", pmf, PM_DEVICE(dip)))
                if (scanp->ps_scan_id) {
                        scanid = scanp->ps_scan_id;
                        scanp->ps_scan_id = 0;
                        PM_UNLOCK_DIP(dip);
                        (void) untimeout(scanid);
                        PM_LOCK_DIP(dip);
                        if (scanp->ps_scan_id) {
                                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): a competing "
                                    "thread scheduled pm_rescan, scanid %lx\n",
                                    pmf, PM_DEVICE(dip),
                                    (ulong_t)scanp->ps_scan_id))
                                PM_UNLOCK_DIP(dip);
                                return;
                        }
                }
                scanp->ps_scan_id = timeout(pm_rescan, (void *)dip,
                    (scanp->ps_idle_down ? pm_id_ticks :
                    (PM_MIN_SCAN(dip) * hz)));
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): scheduled next pm_rescan, "
                    "scanid %lx\n", pmf, PM_DEVICE(dip),
                    (ulong_t)scanp->ps_scan_id))
        } else {
                PMD(PMD_SCAN, ("%s: dispatched pm_scan for %s@%s(%s#%d)\n",
                    pmf, PM_DEVICE(dip)))
                scanp->ps_scan_flags |= PM_SCAN_DISPATCHED;
        }
        PM_UNLOCK_DIP(dip);
}

void
pm_scan(void *arg)
{
        PMD_FUNC(pmf, "scan")
        dev_info_t      *dip = (dev_info_t *)arg;
        pm_scan_t       *scanp;
        time_t          nextscan;

        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))

        PM_LOCK_DIP(dip);
        scanp = PM_GET_PM_SCAN(dip);
        ASSERT(scanp && PM_GET_PM_INFO(dip));

        if (pm_scans_disabled || !PM_SCANABLE(dip) ||
            (scanp->ps_scan_flags & PM_SCAN_STOP)) {
                scanp->ps_scan_flags &= ~(PM_SCAN_AGAIN | PM_SCAN_DISPATCHED);
                PM_UNLOCK_DIP(dip);
                return;
        }

        if (scanp->ps_idle_down) {
                /*
                 * make sure we remember idledown was in affect until
                 * we've completed the scan
                 */
                PMID_SET_SCANS(scanp->ps_idle_down)
                PMD(PMD_IDLEDOWN, ("%s: %s@%s(%s#%d): idledown starts "
                    "(pmid %x)\n", pmf, PM_DEVICE(dip), scanp->ps_idle_down))
        }

        /* possible having two threads running pm_scan() */
        if (scanp->ps_scan_flags & PM_SCANNING) {
                scanp->ps_scan_flags |= PM_SCAN_AGAIN;
                PMD(PMD_SCAN, ("%s: scanning, will scan %s@%s(%s#%d) again\n",
                    pmf, PM_DEVICE(dip)))
                scanp->ps_scan_flags &= ~PM_SCAN_DISPATCHED;
                PM_UNLOCK_DIP(dip);
                return;
        }

        scanp->ps_scan_flags |= PM_SCANNING;
        scanp->ps_scan_flags &= ~PM_SCAN_DISPATCHED;
        do {
                scanp->ps_scan_flags &= ~PM_SCAN_AGAIN;
                PM_UNLOCK_DIP(dip);
                nextscan = pm_scan_dev(dip);
                PM_LOCK_DIP(dip);
        } while (scanp->ps_scan_flags & PM_SCAN_AGAIN);

        ASSERT(scanp->ps_scan_flags & PM_SCANNING);
        scanp->ps_scan_flags &= ~PM_SCANNING;

        if (scanp->ps_idle_down) {
                scanp->ps_idle_down &= ~PMID_SCANS;
                PMD(PMD_IDLEDOWN, ("%s: %s@%s(%s#%d): idledown ends "
                    "(pmid %x)\n", pmf, PM_DEVICE(dip), scanp->ps_idle_down))
        }

        /* schedule for next idle check */
        if (nextscan != LONG_MAX) {
                if (nextscan > (LONG_MAX / hz))
                        nextscan = (LONG_MAX - 1) / hz;
                if (scanp->ps_scan_id) {
                        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): while scanning "
                            "another rescan scheduled scanid(%lx)\n", pmf,
                            PM_DEVICE(dip), (ulong_t)scanp->ps_scan_id))
                        PM_UNLOCK_DIP(dip);
                        return;
                } else if (!(scanp->ps_scan_flags & PM_SCAN_STOP)) {
                        scanp->ps_scan_id = timeout(pm_rescan, (void *)dip,
                            (clock_t)(nextscan * hz));
                        PMD(PMD_SCAN, ("%s: nextscan for %s@%s(%s#%d) in "
                            "%lx sec, scanid(%lx) \n", pmf, PM_DEVICE(dip),
                            (ulong_t)nextscan, (ulong_t)scanp->ps_scan_id))
                }
        }
        PM_UNLOCK_DIP(dip);
}

void
pm_get_timestamps(dev_info_t *dip, time_t *valuep)
{
        int components = PM_NUMCMPTS(dip);
        int i;

        ASSERT(components > 0);
        PM_LOCK_BUSY(dip);      /* so we get a consistent view */
        for (i = 0; i < components; i++) {
                valuep[i] = PM_CP(dip, i)->pmc_timestamp;
        }
        PM_UNLOCK_BUSY(dip);
}

/*
 * Returns true if device needs to be kept up because it exported the
 * "no-involuntary-power-cycles" property or we're pretending it did (console
 * fb case) or it is an ancestor of such a device and has used up the "one
 * free cycle" allowed when all such leaf nodes have voluntarily powered down
 * upon detach
 */
int
pm_noinvol(dev_info_t *dip)
{
        PMD_FUNC(pmf, "noinvol")

        /*
         * This doesn't change over the life of a driver, so no locking needed
         */
        if (PM_IS_CFB(dip)) {
                PMD(PMD_NOINVOL | PMD_CFB, ("%s: inhibits CFB %s@%s(%s#%d)\n",
                    pmf, PM_DEVICE(dip)))
                return (1);
        }
        /*
         * Not an issue if no such kids
         */
        if (DEVI(dip)->devi_pm_noinvolpm == 0) {
#ifdef DEBUG
                if (DEVI(dip)->devi_pm_volpmd != 0) {
                        dev_info_t *pdip = dip;
                        do {
                                PMD(PMD_NOINVOL, ("%s: %s@%s(%s#%d) noinvol %d "
                                    "volpmd %d\n", pmf, PM_DEVICE(pdip),
                                    DEVI(pdip)->devi_pm_noinvolpm,
                                    DEVI(pdip)->devi_pm_volpmd))
                                pdip = ddi_get_parent(pdip);
                        } while (pdip);
                }
#endif
                ASSERT(DEVI(dip)->devi_pm_volpmd == 0);
                return (0);
        }

        /*
         * Since we now maintain the counts correct at every node, we no longer
         * need to look up the tree.  An ancestor cannot use up the free cycle
         * without the children getting their counts adjusted.
         */

#ifdef  DEBUG
        if (DEVI(dip)->devi_pm_noinvolpm != DEVI(dip)->devi_pm_volpmd)
                PMD(PMD_NOINVOL, ("%s: (%d != %d) inhibits %s@%s(%s#%d)\n", pmf,
                    DEVI(dip)->devi_pm_noinvolpm, DEVI(dip)->devi_pm_volpmd,
                    PM_DEVICE(dip)))
#endif
        return (DEVI(dip)->devi_pm_noinvolpm != DEVI(dip)->devi_pm_volpmd);
}

static int      cur_threshold(dev_info_t *, int);
static int      pm_next_lower_power(pm_component_t *, int);

/*
 * This function performs the actual scanning of the device.
 * It attempts to power off the indicated device's components if they have
 * been idle and other restrictions are met.
 * pm_scan_dev calculates and returns when the next scan should happen for
 * this device.
 */
time_t
pm_scan_dev(dev_info_t *dip)
{
        PMD_FUNC(pmf, "scan_dev")
        pm_scan_t       *scanp;
        time_t          *timestamp, idletime, now, thresh;
        time_t          timeleft = 0;
#ifdef PMDDEBUG
        int             curpwr;
#endif
        int             i, nxtpwr, pwrndx, unused;
        size_t          size;
        pm_component_t   *cp;
        dev_info_t      *pdip = ddi_get_parent(dip);
        int             circ;
        clock_t         min_scan = pm_default_min_scan;

        /*
         * skip attaching device
         */
        if (DEVI_IS_ATTACHING(dip)) {
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) is attaching, timeleft(%lx)\n",
                    pmf, PM_DEVICE(dip), min_scan))
                return (min_scan);
        }

        PM_LOCK_DIP(dip);
        scanp = PM_GET_PM_SCAN(dip);
        min_scan = PM_MIN_SCAN(dip);
        ASSERT(scanp && PM_GET_PM_INFO(dip));

        PMD(PMD_SCAN, ("%s: [BEGIN %s@%s(%s#%d)]\n", pmf, PM_DEVICE(dip)))
        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d): kuc is %d\n", pmf, PM_DEVICE(dip),
            PM_KUC(dip)))

        /* no scan under the following conditions */
        if (pm_scans_disabled || !PM_SCANABLE(dip) ||
            (scanp->ps_scan_flags & PM_SCAN_STOP) ||
            (PM_KUC(dip) != 0) ||
            PM_ISDIRECT(dip) || pm_noinvol(dip)) {
                PM_UNLOCK_DIP(dip);
                PMD(PMD_SCAN, ("%s: [END, %s@%s(%s#%d)] no scan, "
                    "scan_disabled(%d), apm_enabled(%d), cpupm(%d), "
                    "kuc(%d), %s directpm, %s pm_noinvol\n",
                    pmf, PM_DEVICE(dip), pm_scans_disabled, autopm_enabled,
                    cpupm, PM_KUC(dip),
                    PM_ISDIRECT(dip) ? "is" : "is not",
                    pm_noinvol(dip) ? "is" : "is not"))
                return (LONG_MAX);
        }
        PM_UNLOCK_DIP(dip);

        if (!ndi_devi_tryenter(pdip, &circ)) {
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) can't hold pdip",
                    pmf, PM_DEVICE(pdip)))
                return ((time_t)1);
        }
        now = gethrestime_sec();
        size = PM_NUMCMPTS(dip) * sizeof (time_t);
        timestamp = kmem_alloc(size, KM_SLEEP);
        pm_get_timestamps(dip, timestamp);

        /*
         * Since we removed support for backwards compatible devices,
         * (see big comment at top of file)
         * it is no longer required to deal with component 0 last.
         */
        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                /*
                 * If already off (an optimization, perhaps)
                 */
                cp = PM_CP(dip, i);
                pwrndx = cp->pmc_cur_pwr;
#ifdef PMDDEBUG
                curpwr = (pwrndx == PM_LEVEL_UNKNOWN) ?
                    PM_LEVEL_UNKNOWN :
                    cp->pmc_comp.pmc_lvals[pwrndx];
#endif

                if (pwrndx == 0) {
                        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) comp %d off or "
                            "lowest\n", pmf, PM_DEVICE(dip), i))
                        /* skip device if off or at its lowest */
                        continue;
                }

                thresh = cur_threshold(dip, i);         /* comp i threshold */
                if ((timestamp[i] == 0) || (cp->pmc_busycount > 0)) {
                        /* were busy or newly became busy by another thread */
                        if (timeleft == 0)
                                timeleft = max(thresh, min_scan);
                        else
                                timeleft = min(
                                    timeleft, max(thresh, min_scan));
                        continue;
                }

                idletime = now - timestamp[i];          /* idle time */
                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) comp %d idle time %lx\n",
                    pmf, PM_DEVICE(dip), i, idletime))
                if (idletime >= thresh || PM_IS_PID(dip)) {
                        nxtpwr = pm_next_lower_power(cp, pwrndx);
                        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) comp %d, %d->%d\n",
                            pmf, PM_DEVICE(dip), i, curpwr, nxtpwr))
                        if (pm_set_power(dip, i, nxtpwr, PM_LEVEL_DOWNONLY,
                            PM_CANBLOCK_FAIL, 1, &unused) != DDI_SUCCESS &&
                            PM_CURPOWER(dip, i) != nxtpwr) {
                                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) comp %d, "
                                    "%d->%d Failed\n", pmf, PM_DEVICE(dip),
                                    i, curpwr, nxtpwr))
                                timeleft = min_scan;
                                continue;
                        } else {
                                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) comp %d, "
                                    "%d->%d, GOOD curpwr %d\n", pmf,
                                    PM_DEVICE(dip), i, curpwr, nxtpwr,
                                    cur_power(cp)))

                                if (nxtpwr == 0)        /* component went off */
                                        continue;

                                /*
                                 * scan to next lower level
                                 */
                                if (timeleft == 0)
                                        timeleft = max(
                                            1, cur_threshold(dip, i));
                                else
                                        timeleft = min(timeleft,
                                            max(1, cur_threshold(dip, i)));
                                PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) comp %d, "
                                    "timeleft(%lx)\n", pmf, PM_DEVICE(dip),
                                    i, timeleft))
                        }
                } else {        /* comp not idle long enough */
                        if (timeleft == 0)
                                timeleft = thresh - idletime;
                        else
                                timeleft = min(timeleft, (thresh - idletime));
                        PMD(PMD_SCAN, ("%s: %s@%s(%s#%d) comp %d, timeleft="
                            "%lx\n", pmf, PM_DEVICE(dip), i, timeleft))
                }
        }
        ndi_devi_exit(pdip, circ);
        kmem_free(timestamp, size);
        PMD(PMD_SCAN, ("%s: [END %s@%s(%s#%d)] timeleft(%lx)\n", pmf,
            PM_DEVICE(dip), timeleft))

        /*
         * if components are already at lowest level, timeleft is left 0
         */
        return ((timeleft == 0) ? LONG_MAX : timeleft);
}

/*
 * pm_scan_stop - cancel scheduled pm_rescan,
 *                wait for termination of dispatched pm_scan thread
 *                     and active pm_scan_dev thread.
 */
void
pm_scan_stop(dev_info_t *dip)
{
        PMD_FUNC(pmf, "scan_stop")
        pm_scan_t       *scanp;
        timeout_id_t    scanid;

        PMD(PMD_SCAN, ("%s: [BEGIN %s@%s(%s#%d)]\n", pmf, PM_DEVICE(dip)))
        PM_LOCK_DIP(dip);
        scanp = PM_GET_PM_SCAN(dip);
        if (!scanp) {
                PMD(PMD_SCAN, ("%s: [END %s@%s(%s#%d)] scan not initialized\n",
                    pmf, PM_DEVICE(dip)))
                PM_UNLOCK_DIP(dip);
                return;
        }
        scanp->ps_scan_flags |= PM_SCAN_STOP;

        /* cancel scheduled scan taskq */
        while (scanp->ps_scan_id) {
                scanid = scanp->ps_scan_id;
                scanp->ps_scan_id = 0;
                PM_UNLOCK_DIP(dip);
                (void) untimeout(scanid);
                PM_LOCK_DIP(dip);
        }

        while (scanp->ps_scan_flags & (PM_SCANNING | PM_SCAN_DISPATCHED)) {
                PM_UNLOCK_DIP(dip);
                delay(1);
                PM_LOCK_DIP(dip);
        }
        PM_UNLOCK_DIP(dip);
        PMD(PMD_SCAN, ("%s: [END %s@%s(%s#%d)]\n", pmf, PM_DEVICE(dip)))
}

int
pm_scan_stop_walk(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))

        if (!PM_GET_PM_SCAN(dip))
                return (DDI_WALK_CONTINUE);
        ASSERT(!PM_ISBC(dip));
        pm_scan_stop(dip);
        return (DDI_WALK_CONTINUE);
}

/*
 * Converts a power level value to its index
 */
static int
power_val_to_index(pm_component_t *cp, int val)
{
        int limit, i, *ip;

        ASSERT(val != PM_LEVEL_UPONLY && val != PM_LEVEL_DOWNONLY &&
            val != PM_LEVEL_EXACT);
        /*  convert power value into index (i) */
        limit = cp->pmc_comp.pmc_numlevels;
        ip = cp->pmc_comp.pmc_lvals;
        for (i = 0; i < limit; i++)
                if (val == *ip++)
                        return (i);
        return (-1);
}

/*
 * Converts a numeric power level to a printable string
 */
static char *
power_val_to_string(pm_component_t *cp, int val)
{
        int index;

        if (val == PM_LEVEL_UPONLY)
                return ("<UPONLY>");

        if (val == PM_LEVEL_UNKNOWN ||
            (index = power_val_to_index(cp, val)) == -1)
                return ("<LEVEL_UNKNOWN>");

        return (cp->pmc_comp.pmc_lnames[index]);
}

/*
 * Return true if this node has been claimed by a ppm.
 */
static int
pm_ppm_claimed(dev_info_t *dip)
{
        return (PPM(dip) != NULL);
}

/*
 * A node which was voluntarily power managed has just used up its "free cycle"
 * and need is volpmd field cleared, and the same done to all its descendents
 */
static void
pm_clear_volpm_dip(dev_info_t *dip)
{
        PMD_FUNC(pmf, "clear_volpm_dip")

        if (dip == NULL)
                return;
        PMD(PMD_NOINVOL, ("%s: clear volpm from %s@%s(%s#%d)\n", pmf,
            PM_DEVICE(dip)))
        DEVI(dip)->devi_pm_volpmd = 0;
        for (dip = ddi_get_child(dip); dip; dip = ddi_get_next_sibling(dip)) {
                pm_clear_volpm_dip(dip);
        }
}

/*
 * A node which was voluntarily power managed has used up the "free cycles"
 * for the subtree that it is the root of.  Scan through the list of detached
 * nodes and adjust the counts of any that are descendents of the node.
 */
static void
pm_clear_volpm_list(dev_info_t *dip)
{
        PMD_FUNC(pmf, "clear_volpm_list")
        char    *pathbuf;
        size_t  len;
        pm_noinvol_t *ip;

        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);
        len = strlen(pathbuf);
        PMD(PMD_NOINVOL, ("%s: clear volpm list %s\n", pmf, pathbuf))
        rw_enter(&pm_noinvol_rwlock, RW_WRITER);
        for (ip = pm_noinvol_head; ip; ip = ip->ni_next) {
                PMD(PMD_NOINVOL, ("%s: clear volpm: ni_path %s\n", pmf,
                    ip->ni_path))
                if (strncmp(pathbuf, ip->ni_path, len) == 0 &&
                    ip->ni_path[len] == '/') {
                        PMD(PMD_NOINVOL, ("%s: clear volpm: %s\n", pmf,
                            ip->ni_path))
                        ip->ni_volpmd = 0;
                        ip->ni_wasvolpmd = 0;
                }
        }
        kmem_free(pathbuf, MAXPATHLEN);
        rw_exit(&pm_noinvol_rwlock);
}

/*
 * Powers a device, suspending or resuming the driver if it is a backward
 * compatible device, calling into ppm to change power level.
 * Called with the component's power lock held.
 */
static int
power_dev(dev_info_t *dip, int comp, int level, int old_level,
    pm_canblock_t canblock, pm_ppm_devlist_t **devlist)
{
        PMD_FUNC(pmf, "power_dev")
        power_req_t power_req;
        int             power_op_ret;   /* DDI_SUCCESS or DDI_FAILURE */
        int             resume_needed = 0;
        int             suspended = 0;
        int             result;
#ifdef PMDDEBUG
        struct pm_component *cp = PM_CP(dip, comp);
#endif
        int             bc = PM_ISBC(dip);
        int pm_all_components_off(dev_info_t *);
        int             clearvolpmd = 0;
        char            pathbuf[MAXNAMELEN];
#ifdef PMDDEBUG
        char *ppmname, *ppmaddr;
#endif
        /*
         * If this is comp 0 of a backwards compat device and we are
         * going to take the power away, we need to detach it with
         * DDI_PM_SUSPEND command.
         */
        if (bc && comp == 0 && POWERING_OFF(old_level, level)) {
                if (devi_detach(dip, DDI_PM_SUSPEND) != DDI_SUCCESS) {
                        /* We could not suspend before turning cmpt zero off */
                        PMD(PMD_ERROR, ("%s: could not suspend %s@%s(%s#%d)\n",
                            pmf, PM_DEVICE(dip)))
                        return (DDI_FAILURE);
                } else {
                        DEVI(dip)->devi_pm_flags |= PMC_SUSPENDED;
                        suspended++;
                }
        }
        power_req.request_type = PMR_PPM_SET_POWER;
        power_req.req.ppm_set_power_req.who = dip;
        power_req.req.ppm_set_power_req.cmpt = comp;
        power_req.req.ppm_set_power_req.old_level = old_level;
        power_req.req.ppm_set_power_req.new_level = level;
        power_req.req.ppm_set_power_req.canblock = canblock;
        power_req.req.ppm_set_power_req.cookie = NULL;
#ifdef PMDDEBUG
        if (pm_ppm_claimed(dip)) {
                ppmname = PM_NAME(PPM(dip));
                ppmaddr = PM_ADDR(PPM(dip));

        } else {
                ppmname = "noppm";
                ppmaddr = "0";
        }
        PMD(PMD_PPM, ("%s: %s@%s(%s#%d):%s[%d] %s (%d) -> %s (%d) via %s@%s\n",
            pmf, PM_DEVICE(dip), cp->pmc_comp.pmc_name, comp,
            power_val_to_string(cp, old_level), old_level,
            power_val_to_string(cp, level), level, ppmname, ppmaddr))
#endif
        /*
         * If non-bc noinvolpm device is turning first comp on, or noinvolpm
         * bc device comp 0 is powering on, then we count it as a power cycle
         * against its voluntary count.
         */
        if (DEVI(dip)->devi_pm_volpmd &&
            (!bc && pm_all_components_off(dip) && level != 0) ||
            (bc && comp == 0 && POWERING_ON(old_level, level)))
                clearvolpmd = 1;
        if ((power_op_ret = pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER,
            &power_req, &result)) == DDI_SUCCESS) {
                /*
                 * Now do involuntary pm accounting;  If we've just cycled power
                 * on a voluntarily pm'd node, and by inference on its entire
                 * subtree, we need to set the subtree (including those nodes
                 * already detached) volpmd counts to 0, and subtract out the
                 * value of the current node's volpmd count from the ancestors
                 */
                if (clearvolpmd) {
                        int volpmd = DEVI(dip)->devi_pm_volpmd;
                        pm_clear_volpm_dip(dip);
                        pm_clear_volpm_list(dip);
                        if (volpmd) {
                                (void) ddi_pathname(dip, pathbuf);
                                (void) pm_noinvol_update(PM_BP_NOINVOL_POWER,
                                    volpmd, 0, pathbuf, dip);
                        }
                }
        } else {
                PMD(PMD_FAIL, ("%s: can't set comp %d (%s) of %s@%s(%s#%d) "
                    "to level %d (%s)\n", pmf, comp, cp->pmc_comp.pmc_name,
                    PM_DEVICE(dip), level, power_val_to_string(cp, level)))
        }
        /*
         * If some other devices were also powered up (e.g. other cpus in
         * the same domain) return a pointer to that list
         */
        if (devlist) {
                *devlist = (pm_ppm_devlist_t *)
                    power_req.req.ppm_set_power_req.cookie;
        }
        /*
         * We will have to resume the device if the device is backwards compat
         * device and either of the following is true:
         * -This is comp 0 and we have successfully powered it up
         * -This is comp 0 and we have failed to power it down. Resume is
         *  needed because we have suspended it above
         */

        if (bc && comp == 0) {
                ASSERT(PM_ISDIRECT(dip) || DEVI_IS_DETACHING(dip));
                if (power_op_ret == DDI_SUCCESS) {
                        if (POWERING_ON(old_level, level)) {
                                /*
                                 * It must be either suspended or resumed
                                 * via pm_power_has_changed path
                                 */
                                ASSERT((DEVI(dip)->devi_pm_flags &
                                    PMC_SUSPENDED) ||
                                    (PM_CP(dip, comp)->pmc_flags &
                                    PM_PHC_WHILE_SET_POWER));

                                        resume_needed = suspended;
                        }
                } else {
                        if (POWERING_OFF(old_level, level)) {
                                /*
                                 * It must be either suspended or resumed
                                 * via pm_power_has_changed path
                                 */
                                ASSERT((DEVI(dip)->devi_pm_flags &
                                    PMC_SUSPENDED) ||
                                    (PM_CP(dip, comp)->pmc_flags &
                                    PM_PHC_WHILE_SET_POWER));

                                        resume_needed = suspended;
                        }
                }
        }
        if (resume_needed) {
                ASSERT(DEVI(dip)->devi_pm_flags & PMC_SUSPENDED);
                /* ppm is not interested in DDI_PM_RESUME */
                if ((power_op_ret = devi_attach(dip, DDI_PM_RESUME)) ==
                    DDI_SUCCESS) {
                        DEVI(dip)->devi_pm_flags &= ~PMC_SUSPENDED;
                } else
                        cmn_err(CE_WARN, "!pm: Can't resume %s@%s(%s#%d)",
                            PM_DEVICE(dip));
        }
        return (power_op_ret);
}

/*
 * Return true if we are the owner or a borrower of the devi lock.  See
 * pm_lock_power_single() about borrowing the lock.
 */
static int
pm_devi_lock_held(dev_info_t *dip)
{
        lock_loan_t *cur;

        if (DEVI_BUSY_OWNED(dip))
                return (1);

        /* return false if no locks borrowed */
        if (lock_loan_head.pmlk_next == NULL)
                return (0);

        mutex_enter(&pm_loan_lock);
        /* see if our thread is registered as a lock borrower. */
        for (cur = lock_loan_head.pmlk_next; cur; cur = cur->pmlk_next)
                if (cur->pmlk_borrower == curthread)
                        break;
        mutex_exit(&pm_loan_lock);

        return (cur != NULL && cur->pmlk_lender == DEVI(dip)->devi_busy_thread);
}

/*
 * pm_set_power: adjusts power level of device.  Assumes device is power
 * manageable & component exists.
 *
 * Cases which require us to bring up devices we keep up ("wekeepups") for
 * backwards compatible devices:
 *      component 0 is off and we're bringing it up from 0
 *              bring up wekeepup first
 *      and recursively when component 0 is off and we bring some other
 *      component up from 0
 * For devices which are not backward compatible, our dependency notion is much
 * simpler.  Unless all components are off, then wekeeps must be on.
 * We don't treat component 0 differently.
 * Canblock tells how to deal with a direct pm'd device.
 * Scan arg tells us if we were called from scan, in which case we don't need
 * to go back to the root node and walk down to change power.
 */
int
pm_set_power(dev_info_t *dip, int comp, int level, int direction,
    pm_canblock_t canblock, int scan, int *retp)
{
        PMD_FUNC(pmf, "set_power")
        char            *pathbuf;
        pm_bp_child_pwrchg_t bpc;
        pm_sp_misc_t    pspm;
        int             ret = DDI_SUCCESS;
        int             unused = DDI_SUCCESS;
        dev_info_t      *pdip = ddi_get_parent(dip);

#ifdef DEBUG
        int             diverted = 0;

        /*
         * This prevents operations on the console from calling prom_printf and
         * either deadlocking or bringing up the console because of debug
         * output
         */
        if (dip == cfb_dip) {
                diverted++;
                mutex_enter(&pm_debug_lock);
                pm_divertdebug++;
                mutex_exit(&pm_debug_lock);
        }
#endif
        ASSERT(direction == PM_LEVEL_UPONLY || direction == PM_LEVEL_DOWNONLY ||
            direction == PM_LEVEL_EXACT);
        PMD(PMD_SET, ("%s: %s@%s(%s#%d), comp=%d, dir=%s, new=%d\n",
            pmf, PM_DEVICE(dip), comp, pm_decode_direction(direction), level))
        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);
        bpc.bpc_dip = dip;
        bpc.bpc_path = pathbuf;
        bpc.bpc_comp = comp;
        bpc.bpc_olevel = PM_CURPOWER(dip, comp);
        bpc.bpc_nlevel = level;
        pspm.pspm_direction = direction;
        pspm.pspm_errnop = retp;
        pspm.pspm_canblock = canblock;
        pspm.pspm_scan = scan;
        bpc.bpc_private = &pspm;

        /*
         * If a config operation is being done (we've locked the parent) or
         * we already hold the power lock (we've locked the node)
         * then we can operate directly on the node because we have already
         * brought up all the ancestors, otherwise, we have to go back to the
         * top of the tree.
         */
        if (pm_devi_lock_held(pdip) || pm_devi_lock_held(dip))
                ret = pm_busop_set_power(dip, NULL, BUS_POWER_CHILD_PWRCHG,
                    (void *)&bpc, (void *)&unused);
        else
                ret = pm_busop_bus_power(ddi_root_node(), NULL,
                    BUS_POWER_CHILD_PWRCHG, (void *)&bpc, (void *)&unused);
#ifdef DEBUG
        if (ret != DDI_SUCCESS || *retp != DDI_SUCCESS) {
                PMD(PMD_ERROR, ("%s: %s@%s(%s#%d) can't change power, ret=%d, "
                    "errno=%d\n", pmf, PM_DEVICE(dip), ret, *retp))
        }
        if (diverted) {
                mutex_enter(&pm_debug_lock);
                pm_divertdebug--;
                mutex_exit(&pm_debug_lock);
        }
#endif
        kmem_free(pathbuf, MAXPATHLEN);
        return (ret);
}

/*
 * If holddip is set, then if a dip is found we return with the node held.
 *
 * This code uses the same locking scheme as e_ddi_hold_devi_by_path
 * (resolve_pathname), but it does not drive attach.
 */
dev_info_t *
pm_name_to_dip(char *pathname, int holddip)
{
        struct pathname pn;
        char            *component;
        dev_info_t      *parent, *child;
        int             circ;

        if ((pathname == NULL) || (*pathname != '/'))
                return (NULL);

        /* setup pathname and allocate component */
        if (pn_get(pathname, UIO_SYSSPACE, &pn))
                return (NULL);
        component = kmem_alloc(MAXNAMELEN, KM_SLEEP);

        /* start at top, process '/' component */
        parent = child = ddi_root_node();
        ndi_hold_devi(parent);
        pn_skipslash(&pn);
        ASSERT(i_ddi_devi_attached(parent));

        /* process components of pathname */
        while (pn_pathleft(&pn)) {
                (void) pn_getcomponent(&pn, component);

                /* enter parent and search for component child */
                ndi_devi_enter(parent, &circ);
                child = ndi_devi_findchild(parent, component);
                if ((child == NULL) || !i_ddi_devi_attached(child)) {
                        child = NULL;
                        ndi_devi_exit(parent, circ);
                        ndi_rele_devi(parent);
                        goto out;
                }

                /* attached child found, hold child and release parent */
                ndi_hold_devi(child);
                ndi_devi_exit(parent, circ);
                ndi_rele_devi(parent);

                /* child becomes parent, and process next component */
                parent = child;
                pn_skipslash(&pn);

                /* loop with active ndi_devi_hold of child->parent */
        }

out:
        pn_free(&pn);
        kmem_free(component, MAXNAMELEN);

        /* if we are not asked to return with hold, drop current hold */
        if (child && !holddip)
                ndi_rele_devi(child);
        return (child);
}

/*
 * Search for a dependency and mark it unsatisfied
 */
static void
pm_unsatisfy(char *keeper, char *kept)
{
        PMD_FUNC(pmf, "unsatisfy")
        pm_pdr_t *dp;

        PMD(PMD_KEEPS, ("%s: keeper=%s, kept=%s\n", pmf, keeper, kept))
        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (!dp->pdr_isprop) {
                        if (strcmp(dp->pdr_keeper, keeper) == 0 &&
                            (dp->pdr_kept_count > 0) &&
                            strcmp(dp->pdr_kept_paths[0], kept) == 0) {
                                if (dp->pdr_satisfied) {
                                        dp->pdr_satisfied = 0;
                                        pm_unresolved_deps++;
                                        PMD(PMD_KEEPS, ("%s: clear satisfied, "
                                            "pm_unresolved_deps now %d\n", pmf,
                                            pm_unresolved_deps))
                                }
                        }
                }
        }
}

/*
 * Device dip is being un power managed, it keeps up count other devices.
 * We need to release any hold we have on the kept devices, and also
 * mark the dependency no longer satisfied.
 */
static void
pm_unkeeps(int count, char *keeper, char **keptpaths, int pwr)
{
        PMD_FUNC(pmf, "unkeeps")
        int i, j;
        dev_info_t *kept;
        dev_info_t *dip;
        struct pm_component *cp;
        int keeper_on = 0, circ;

        PMD(PMD_KEEPS, ("%s: count=%d, keeper=%s, keptpaths=%p\n", pmf, count,
            keeper, (void *)keptpaths))
        /*
         * Try to grab keeper. Keeper may have gone away by now,
         * in this case, used the passed in value pwr
         */
        dip = pm_name_to_dip(keeper, 1);
        for (i = 0; i < count; i++) {
                /* Release power hold */
                kept = pm_name_to_dip(keptpaths[i], 1);
                if (kept) {
                        PMD(PMD_KEEPS, ("%s: %s@%s(%s#%d)[%d]\n", pmf,
                            PM_DEVICE(kept), i))
                        /*
                         * We need to check if we skipped a bringup here
                         * because we could have failed the bringup
                         * (ie DIRECT PM device) and have
                         * not increment the count.
                         */
                        if ((dip != NULL) && (PM_GET_PM_INFO(dip) != NULL)) {
                                keeper_on = 0;
                                PM_LOCK_POWER(dip, &circ);
                                for (j = 0; j < PM_NUMCMPTS(dip); j++) {
                                        cp = &DEVI(dip)->devi_pm_components[j];
                                        if (cur_power(cp)) {
                                                keeper_on++;
                                                break;
                                        }
                                }
                                if (keeper_on && (PM_SKBU(kept) == 0)) {
                                        pm_rele_power(kept);
                                        DEVI(kept)->devi_pm_flags
                                            &= ~PMC_SKIP_BRINGUP;
                                }
                                PM_UNLOCK_POWER(dip, circ);
                        } else if (pwr) {
                                if (PM_SKBU(kept) == 0) {
                                        pm_rele_power(kept);
                                        DEVI(kept)->devi_pm_flags
                                            &= ~PMC_SKIP_BRINGUP;
                                }
                        }
                        ddi_release_devi(kept);
                }
                /*
                 * mark this dependency not satisfied
                 */
                pm_unsatisfy(keeper, keptpaths[i]);
        }
        if (dip)
                ddi_release_devi(dip);
}

/*
 * Device kept is being un power managed, it is kept up by keeper.
 * We need to mark the dependency no longer satisfied.
 */
static void
pm_unkepts(char *kept, char *keeper)
{
        PMD_FUNC(pmf, "unkepts")
        PMD(PMD_KEEPS, ("%s: kept=%s, keeper=%s\n", pmf, kept, keeper))
        ASSERT(keeper != NULL);
        /*
         * mark this dependency not satisfied
         */
        pm_unsatisfy(keeper, kept);
}

/*
 * Removes dependency information and hold on the kepts, if the path is a
 * path of a keeper.
 */
static void
pm_free_keeper(char *path, int pwr)
{
        pm_pdr_t *dp;
        int i;
        size_t length;

        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (strcmp(dp->pdr_keeper, path) != 0)
                        continue;
                /*
                 * Remove all our kept holds and the dependency records,
                 * then free up the kept lists.
                 */
                pm_unkeeps(dp->pdr_kept_count, path, dp->pdr_kept_paths, pwr);
                if (dp->pdr_kept_count)  {
                        for (i = 0; i < dp->pdr_kept_count; i++) {
                                length = strlen(dp->pdr_kept_paths[i]);
                                kmem_free(dp->pdr_kept_paths[i], length + 1);
                        }
                        kmem_free(dp->pdr_kept_paths,
                            dp->pdr_kept_count * sizeof (char **));
                        dp->pdr_kept_paths = NULL;
                        dp->pdr_kept_count = 0;
                }
        }
}

/*
 * Removes the device represented by path from the list of kepts, if the
 * path is a path of a kept
 */
static void
pm_free_kept(char *path)
{
        pm_pdr_t *dp;
        int i;
        int j, count;
        size_t length;
        char **paths;

        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (dp->pdr_kept_count == 0)
                        continue;
                count = dp->pdr_kept_count;
                /* Remove this device from the kept path lists */
                for (i = 0; i < count; i++) {
                        if (strcmp(dp->pdr_kept_paths[i], path) == 0) {
                                pm_unkepts(path, dp->pdr_keeper);
                                length = strlen(dp->pdr_kept_paths[i]) + 1;
                                kmem_free(dp->pdr_kept_paths[i], length);
                                dp->pdr_kept_paths[i] = NULL;
                                dp->pdr_kept_count--;
                        }
                }
                /* Compact the kept paths array */
                if (dp->pdr_kept_count) {
                        length = dp->pdr_kept_count * sizeof (char **);
                        paths = kmem_zalloc(length, KM_SLEEP);
                        j = 0;
                        for (i = 0; i < count; i++) {
                                if (dp->pdr_kept_paths[i] != NULL) {
                                        paths[j] = dp->pdr_kept_paths[i];
                                        j++;
                                }
                        }
                        ASSERT(j == dp->pdr_kept_count);
                }
                /* Now free the old array and point to the new one */
                kmem_free(dp->pdr_kept_paths, count * sizeof (char **));
                if (dp->pdr_kept_count)
                        dp->pdr_kept_paths = paths;
                else
                        dp->pdr_kept_paths = NULL;
        }
}

/*
 * Free the dependency information for a device.
 */
void
pm_free_keeps(char *path, int pwr)
{
        PMD_FUNC(pmf, "free_keeps")

#ifdef DEBUG
        int doprdeps = 0;
        void prdeps(char *);

        PMD(PMD_KEEPS, ("%s: %s\n", pmf, path))
        if (pm_debug & PMD_KEEPS) {
                doprdeps = 1;
                prdeps("pm_free_keeps before");
        }
#endif
        /*
         * First assume we are a keeper and remove all our kepts.
         */
        pm_free_keeper(path, pwr);
        /*
         * Now assume we a kept device, and remove all our records.
         */
        pm_free_kept(path);
#ifdef  DEBUG
        if (doprdeps) {
                prdeps("pm_free_keeps after");
        }
#endif
}

static int
pm_is_kept(char *path)
{
        pm_pdr_t *dp;
        int i;

        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (dp->pdr_kept_count == 0)
                        continue;
                for (i = 0; i < dp->pdr_kept_count; i++) {
                        if (strcmp(dp->pdr_kept_paths[i], path) == 0)
                                return (1);
                }
        }
        return (0);
}

static void
e_pm_hold_rele_power(dev_info_t *dip, int cnt)
{
        PMD_FUNC(pmf, "hold_rele_power")
        int circ;

        if ((dip == NULL) ||
            (PM_GET_PM_INFO(dip) == NULL) || PM_ISBC(dip))
                return;

        PM_LOCK_POWER(dip, &circ);
        ASSERT(cnt >= 0 && PM_KUC(dip) >= 0 || cnt < 0 && PM_KUC(dip) > 0);
        PMD(PMD_KIDSUP, ("%s: kidsupcnt for %s@%s(%s#%d) %d->%d\n", pmf,
            PM_DEVICE(dip), PM_KUC(dip), (PM_KUC(dip) + cnt)))

        PM_KUC(dip) += cnt;

        ASSERT(PM_KUC(dip) >= 0);
        PM_UNLOCK_POWER(dip, circ);

        if (cnt < 0 && PM_KUC(dip) == 0)
                pm_rescan(dip);
}

#define MAX_PPM_HANDLERS        4

kmutex_t ppm_lock;      /* in case we ever do multi-threaded startup */

struct  ppm_callbacks {
        int (*ppmc_func)(dev_info_t *);
        dev_info_t      *ppmc_dip;
} ppm_callbacks[MAX_PPM_HANDLERS + 1];


/*
 * This routine calls into all the registered ppms to notify them
 * that either all components of power-managed devices are at their
 * lowest levels or no longer all are at their lowest levels.
 */
static void
pm_ppm_notify_all_lowest(dev_info_t *dip, int mode)
{
        struct ppm_callbacks *ppmcp;
        power_req_t power_req;
        int result = 0;

        power_req.request_type = PMR_PPM_ALL_LOWEST;
        power_req.req.ppm_all_lowest_req.mode = mode;
        mutex_enter(&ppm_lock);
        for (ppmcp = ppm_callbacks; ppmcp->ppmc_func; ppmcp++)
                (void) pm_ctlops((dev_info_t *)ppmcp->ppmc_dip, dip,
                    DDI_CTLOPS_POWER, &power_req, &result);
        mutex_exit(&ppm_lock);
        if (mode == PM_ALL_LOWEST) {
                if (autoS3_enabled) {
                        PMD(PMD_SX, ("pm_ppm_notify_all_lowest triggering "
                            "autos3\n"))
                        mutex_enter(&srn_clone_lock);
                        if (srn_signal) {
                                srn_inuse++;
                                PMD(PMD_SX, ("(*srn_signal)(AUTOSX, 3)\n"))
                                (*srn_signal)(SRN_TYPE_AUTOSX, 3);
                                srn_inuse--;
                        } else {
                                PMD(PMD_SX, ("srn_signal NULL\n"))
                        }
                        mutex_exit(&srn_clone_lock);
                } else {
                        PMD(PMD_SX, ("pm_ppm_notify_all_lowest autos3 "
                            "disabled\n"));
                }
        }
}

static void
pm_set_pm_info(dev_info_t *dip, void *value)
{
        DEVI(dip)->devi_pm_info = value;
}

pm_rsvp_t *pm_blocked_list;

/*
 * Look up an entry in the blocked list by dip and component
 */
static pm_rsvp_t *
pm_rsvp_lookup(dev_info_t *dip, int comp)
{
        pm_rsvp_t *p;
        ASSERT(MUTEX_HELD(&pm_rsvp_lock));
        for (p = pm_blocked_list; p; p = p->pr_next)
                if (p->pr_dip == dip && p->pr_comp == comp) {
                        return (p);
                }
        return (NULL);
}

/*
 * Called when a device which is direct power managed (or the parent or
 * dependent of such a device) changes power, or when a pm clone is closed
 * that was direct power managing a device.  This call results in pm_blocked()
 * (below) returning.
 */
void
pm_proceed(dev_info_t *dip, int cmd, int comp, int newlevel)
{
        PMD_FUNC(pmf, "proceed")
        pm_rsvp_t *found = NULL;
        pm_rsvp_t *p;

        mutex_enter(&pm_rsvp_lock);
        switch (cmd) {
        /*
         * we're giving up control, let any pending op continue
         */
        case PMP_RELEASE:
                for (p = pm_blocked_list; p; p = p->pr_next) {
                        if (dip == p->pr_dip) {
                                p->pr_retval = PMP_RELEASE;
                                PMD(PMD_DPM, ("%s: RELEASE %s@%s(%s#%d)\n",
                                    pmf, PM_DEVICE(dip)))
                                cv_signal(&p->pr_cv);
                        }
                }
                break;

        /*
         * process has done PM_SET_CURRENT_POWER; let a matching request
         * succeed and a non-matching request for the same device fail
         */
        case PMP_SETPOWER:
                found = pm_rsvp_lookup(dip, comp);
                if (!found)     /* if driver not waiting */
                        break;
                /*
                 * This cannot be pm_lower_power, since that can only happen
                 * during detach or probe
                 */
                if (found->pr_newlevel <= newlevel) {
                        found->pr_retval = PMP_SUCCEED;
                        PMD(PMD_DPM, ("%s: SUCCEED %s@%s(%s#%d)\n", pmf,
                            PM_DEVICE(dip)))
                } else {
                        found->pr_retval = PMP_FAIL;
                        PMD(PMD_DPM, ("%s: FAIL %s@%s(%s#%d)\n", pmf,
                            PM_DEVICE(dip)))
                }
                cv_signal(&found->pr_cv);
                break;

        default:
                panic("pm_proceed unknown cmd %d", cmd);
        }
        mutex_exit(&pm_rsvp_lock);
}

/*
 * This routine dispatches new work to the dependency thread. Caller must
 * be prepared to block for memory if necessary.
 */
void
pm_dispatch_to_dep_thread(int cmd, char *keeper, char *kept, int wait,
    int *res, int cached_pwr)
{
        pm_dep_wk_t     *new_work;

        new_work = kmem_zalloc(sizeof (pm_dep_wk_t), KM_SLEEP);
        new_work->pdw_type = cmd;
        new_work->pdw_wait = wait;
        new_work->pdw_done = 0;
        new_work->pdw_ret = 0;
        new_work->pdw_pwr = cached_pwr;
        cv_init(&new_work->pdw_cv, NULL, CV_DEFAULT, NULL);
        if (keeper != NULL) {
                new_work->pdw_keeper = kmem_zalloc(strlen(keeper) + 1,
                    KM_SLEEP);
                (void) strcpy(new_work->pdw_keeper, keeper);
        }
        if (kept != NULL) {
                new_work->pdw_kept = kmem_zalloc(strlen(kept) + 1, KM_SLEEP);
                (void) strcpy(new_work->pdw_kept, kept);
        }
        mutex_enter(&pm_dep_thread_lock);
        if (pm_dep_thread_workq == NULL) {
                pm_dep_thread_workq = new_work;
                pm_dep_thread_tail = new_work;
                new_work->pdw_next = NULL;
        } else {
                pm_dep_thread_tail->pdw_next = new_work;
                pm_dep_thread_tail = new_work;
                new_work->pdw_next = NULL;
        }
        cv_signal(&pm_dep_thread_cv);
        /* If caller asked for it, wait till it is done. */
        if (wait)  {
                while (!new_work->pdw_done)
                        cv_wait(&new_work->pdw_cv, &pm_dep_thread_lock);
                /*
                 * Pass return status, if any, back.
                 */
                if (res != NULL)
                        *res = new_work->pdw_ret;
                /*
                 * If we asked to wait, it is our job to free the request
                 * structure.
                 */
                if (new_work->pdw_keeper)
                        kmem_free(new_work->pdw_keeper,
                            strlen(new_work->pdw_keeper) + 1);
                if (new_work->pdw_kept)
                        kmem_free(new_work->pdw_kept,
                            strlen(new_work->pdw_kept) + 1);
                kmem_free(new_work, sizeof (pm_dep_wk_t));
        }
        mutex_exit(&pm_dep_thread_lock);
}

/*
 * Release the pm resource for this device.
 */
void
pm_rem_info(dev_info_t *dip)
{
        PMD_FUNC(pmf, "rem_info")
        int             i, count = 0;
        pm_info_t       *info = PM_GET_PM_INFO(dip);
        dev_info_t      *pdip = ddi_get_parent(dip);
        char            *pathbuf;
        int             work_type = PM_DEP_WK_DETACH;

        ASSERT(info);

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        if (PM_ISDIRECT(dip)) {
                info->pmi_dev_pm_state &= ~PM_DIRECT;
                ASSERT(info->pmi_clone);
                info->pmi_clone = 0;
                pm_proceed(dip, PMP_RELEASE, -1, -1);
        }
        ASSERT(!PM_GET_PM_SCAN(dip));

        /*
         * Now adjust parent's kidsupcnt.  BC nodes we check only comp 0,
         * Others we check all components.  BC node that has already
         * called pm_destroy_components() has zero component count.
         * Parents that get notification are not adjusted because their
         * kidsupcnt is always 0 (or 1 during configuration).
         */
        PMD(PMD_KEEPS, ("%s: %s@%s(%s#%d) has %d components\n", pmf,
            PM_DEVICE(dip), PM_NUMCMPTS(dip)))

        /* node is detached, so we can examine power without locking */
        if (PM_ISBC(dip)) {
                count = (PM_CURPOWER(dip, 0) != 0);
        } else {
                for (i = 0; i < PM_NUMCMPTS(dip); i++)
                        count += (PM_CURPOWER(dip, i) != 0);
        }

        if (PM_NUMCMPTS(dip) && pdip && !PM_WANTS_NOTIFICATION(pdip))
                e_pm_hold_rele_power(pdip, -count);

        /* Schedule a request to clean up dependency records */
        pathbuf = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);
        pm_dispatch_to_dep_thread(work_type, pathbuf, pathbuf,
            PM_DEP_NOWAIT, NULL, (count > 0));
        kmem_free(pathbuf, MAXPATHLEN);

        /*
         * Adjust the pm_comps_notlowest count since this device is
         * not being power-managed anymore.
         */
        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                pm_component_t *cp = PM_CP(dip, i);
                if (cp->pmc_cur_pwr != 0)
                        PM_DECR_NOTLOWEST(dip)
        }
        /*
         * Once we clear the info pointer, it looks like it is not power
         * managed to everybody else.
         */
        pm_set_pm_info(dip, NULL);
        kmem_free(info, sizeof (pm_info_t));
}

int
pm_get_norm_pwrs(dev_info_t *dip, int **valuep, size_t *length)
{
        int components = PM_NUMCMPTS(dip);
        int *bufp;
        size_t size;
        int i;

        if (components <= 0) {
                cmn_err(CE_NOTE, "!pm: %s@%s(%s#%d) has no components, "
                    "can't get normal power values\n", PM_DEVICE(dip));
                return (DDI_FAILURE);
        } else {
                size = components * sizeof (int);
                bufp = kmem_alloc(size, KM_SLEEP);
                for (i = 0; i < components; i++) {
                        bufp[i] = pm_get_normal_power(dip, i);
                }
        }
        *length = size;
        *valuep = bufp;
        return (DDI_SUCCESS);
}

static int
pm_reset_timestamps(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))

        int components;
        int     i;

        if (!PM_GET_PM_INFO(dip))
                return (DDI_WALK_CONTINUE);
        components = PM_NUMCMPTS(dip);
        ASSERT(components > 0);
        PM_LOCK_BUSY(dip);
        for (i = 0; i < components; i++) {
                struct pm_component *cp;
                /*
                 * If the component was not marked as busy,
                 * reset its timestamp to now.
                 */
                cp = PM_CP(dip, i);
                if (cp->pmc_timestamp)
                        cp->pmc_timestamp = gethrestime_sec();
        }
        PM_UNLOCK_BUSY(dip);
        return (DDI_WALK_CONTINUE);
}

/*
 * Convert a power level to an index into the levels array (or
 * just PM_LEVEL_UNKNOWN in that special case).
 */
static int
pm_level_to_index(dev_info_t *dip, pm_component_t *cp, int level)
{
        PMD_FUNC(pmf, "level_to_index")
        int i;
        int limit = cp->pmc_comp.pmc_numlevels;
        int *ip = cp->pmc_comp.pmc_lvals;

        if (level == PM_LEVEL_UNKNOWN)
                return (level);

        for (i = 0; i < limit; i++) {
                if (level == *ip++) {
                        PMD(PMD_LEVEL, ("%s: %s@%s(%s#%d)[%d] to %x\n",
                            pmf, PM_DEVICE(dip),
                            (int)(cp - DEVI(dip)->devi_pm_components), level))
                        return (i);
                }
        }
        panic("pm_level_to_index: level %d not found for device "
            "%s@%s(%s#%d)", level, PM_DEVICE(dip));
        /*NOTREACHED*/
}

/*
 * Internal function to set current power level
 */
static void
e_pm_set_cur_pwr(dev_info_t *dip, pm_component_t *cp, int level)
{
        PMD_FUNC(pmf, "set_cur_pwr")
        int curpwr = (cp->pmc_flags & PM_PHC_WHILE_SET_POWER ?
            cp->pmc_phc_pwr : cp->pmc_cur_pwr);

        /*
         * Nothing to adjust if current & new levels are the same.
         */
        if (curpwr != PM_LEVEL_UNKNOWN &&
            level == cp->pmc_comp.pmc_lvals[curpwr])
                return;

        /*
         * Keep the count for comps doing transition to/from lowest
         * level.
         */
        if (curpwr == 0) {
                PM_INCR_NOTLOWEST(dip);
        } else if (level == cp->pmc_comp.pmc_lvals[0]) {
                PM_DECR_NOTLOWEST(dip);
        }
        cp->pmc_phc_pwr = PM_LEVEL_UNKNOWN;
        cp->pmc_cur_pwr = pm_level_to_index(dip, cp, level);
}

static int pm_phc_impl(dev_info_t *, int, int, int);

/*
 * This is the default method of setting the power of a device if no ppm
 * driver has claimed it.
 */
int
pm_power(dev_info_t *dip, int comp, int level)
{
        PMD_FUNC(pmf, "power")
        struct dev_ops  *ops;
        int             (*fn)(dev_info_t *, int, int);
        struct pm_component *cp = PM_CP(dip, comp);
        int retval;
        pm_info_t *info = PM_GET_PM_INFO(dip);

        PMD(PMD_KIDSUP, ("%s: %s@%s(%s#%d), comp=%d, level=%d\n", pmf,
            PM_DEVICE(dip), comp, level))
        if (!(ops = ddi_get_driver(dip))) {
                PMD(PMD_FAIL, ("%s: %s@%s(%s#%d) has no ops\n", pmf,
                    PM_DEVICE(dip)))
                return (DDI_FAILURE);
        }
        if ((ops->devo_rev < 2) || !(fn = ops->devo_power)) {
                PMD(PMD_FAIL, ("%s: %s%s\n", pmf,
                    (ops->devo_rev < 2 ? " wrong devo_rev" : ""),
                    (!fn ? " devo_power NULL" : "")))
                return (DDI_FAILURE);
        }
        cp->pmc_flags |= PM_POWER_OP;
        retval = (*fn)(dip, comp, level);
        cp->pmc_flags &= ~PM_POWER_OP;
        if (retval == DDI_SUCCESS) {
                e_pm_set_cur_pwr(dip, PM_CP(dip, comp), level);
                return (DDI_SUCCESS);
        }

        /*
         * If pm_power_has_changed() detected a deadlock with pm_power() it
         * updated only the power level of the component.  If our attempt to
         * set the device new to a power level above has failed we sync the
         * total power state via phc code now.
         */
        if (cp->pmc_flags & PM_PHC_WHILE_SET_POWER) {
                int phc_lvl =
                    cp->pmc_comp.pmc_lvals[cp->pmc_cur_pwr];

                ASSERT(info);
                (void) pm_phc_impl(dip, comp, phc_lvl, 0);
                PMD(PMD_PHC, ("%s: phc %s@%s(%s#%d) comp=%d level=%d\n",
                    pmf, PM_DEVICE(dip), comp, phc_lvl))
        }

        PMD(PMD_FAIL, ("%s: can't set comp=%d (%s) of %s@%s(%s#%d) to "
            "level=%d (%s)\n", pmf, comp, cp->pmc_comp.pmc_name, PM_DEVICE(dip),
            level, power_val_to_string(cp, level)));
        return (DDI_FAILURE);
}

int
pm_unmanage(dev_info_t *dip)
{
        PMD_FUNC(pmf, "unmanage")
        power_req_t power_req;
        int result, retval = 0;

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        PMD(PMD_REMDEV | PMD_KIDSUP, ("%s: %s@%s(%s#%d)\n", pmf,
            PM_DEVICE(dip)))
        power_req.request_type = PMR_PPM_UNMANAGE;
        power_req.req.ppm_config_req.who = dip;
        if (pm_ppm_claimed(dip))
                retval = pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER,
                    &power_req, &result);
#ifdef DEBUG
        else
                retval = pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER,
                    &power_req, &result);
#endif
        ASSERT(retval == DDI_SUCCESS);
        pm_rem_info(dip);
        return (retval);
}

int
pm_raise_power(dev_info_t *dip, int comp, int level)
{
        if (level < 0)
                return (DDI_FAILURE);
        if (!e_pm_valid_info(dip, NULL) || !e_pm_valid_comp(dip, comp, NULL) ||
            !e_pm_valid_power(dip, comp, level))
                return (DDI_FAILURE);

        return (dev_is_needed(dip, comp, level, PM_LEVEL_UPONLY));
}

int
pm_lower_power(dev_info_t *dip, int comp, int level)
{
        PMD_FUNC(pmf, "pm_lower_power")

        if (!e_pm_valid_info(dip, NULL) || !e_pm_valid_comp(dip, comp, NULL) ||
            !e_pm_valid_power(dip, comp, level)) {
                PMD(PMD_FAIL, ("%s: validation checks failed for %s@%s(%s#%d) "
                    "comp=%d level=%d\n", pmf, PM_DEVICE(dip), comp, level))
                return (DDI_FAILURE);
        }

        if (!DEVI_IS_DETACHING(dip)) {
                PMD(PMD_FAIL, ("%s: %s@%s(%s#%d) not detaching\n",
                    pmf, PM_DEVICE(dip)))
                return (DDI_FAILURE);
        }

        /*
         * If we don't care about saving power, or we're treating this node
         * specially, then this is a no-op
         */
        if (!PM_SCANABLE(dip) || pm_noinvol(dip)) {
                PMD(PMD_FAIL, ("%s: %s@%s(%s#%d) %s%s%s%s\n",
                    pmf, PM_DEVICE(dip),
                    !autopm_enabled ? "!autopm_enabled " : "",
                    !PM_POLLING_CPUPM ? "!cpupm_polling " : "",
                    PM_CPUPM_DISABLED ? "cpupm_disabled " : "",
                    pm_noinvol(dip) ? "pm_noinvol()" : ""))
                return (DDI_SUCCESS);
        }

        if (dev_is_needed(dip, comp, level, PM_LEVEL_DOWNONLY) != DDI_SUCCESS) {
                PMD(PMD_FAIL, ("%s: %s@%s(%s#%d) dev_is_needed failed\n", pmf,
                    PM_DEVICE(dip)))
                return (DDI_FAILURE);
        }
        return (DDI_SUCCESS);
}

/*
 * Find the entries struct for a given dip in the blocked list, return it locked
 */
static psce_t *
pm_psc_dip_to_direct(dev_info_t *dip, pscc_t **psccp)
{
        pscc_t *p;
        psce_t *psce;

        rw_enter(&pm_pscc_direct_rwlock, RW_READER);
        for (p = pm_pscc_direct; p; p = p->pscc_next) {
                if (p->pscc_dip == dip) {
                        *psccp = p;
                        psce = p->pscc_entries;
                        mutex_enter(&psce->psce_lock);
                        ASSERT(psce);
                        rw_exit(&pm_pscc_direct_rwlock);
                        return (psce);
                }
        }
        rw_exit(&pm_pscc_direct_rwlock);
        panic("sunpm: no entry for dip %p in direct list", (void *)dip);
        /*NOTREACHED*/
}

/*
 * Write an entry indicating a power level change (to be passed to a process
 * later) in the given psce.
 * If we were called in the path that brings up the console fb in the
 * case of entering the prom, we don't want to sleep.  If the alloc fails, then
 * we create a record that has a size of -1, a physaddr of NULL, and that
 * has the overflow flag set.
 */
static int
psc_entry(ushort_t event, psce_t *psce, dev_info_t *dip, int comp, int new,
    int old, int which, pm_canblock_t canblock)
{
        char    buf[MAXNAMELEN];
        pm_state_change_t *p;
        size_t  size;
        caddr_t physpath = NULL;
        int     overrun = 0;

        ASSERT(MUTEX_HELD(&psce->psce_lock));
        (void) ddi_pathname(dip, buf);
        size = strlen(buf) + 1;
        p = psce->psce_in;
        if (canblock == PM_CANBLOCK_BYPASS) {
                physpath = kmem_alloc(size, KM_NOSLEEP);
                if (physpath == NULL) {
                        /*
                         * mark current entry as overrun
                         */
                        p->flags |= PSC_EVENT_LOST;
                        size = (size_t)-1;
                }
        } else
                physpath = kmem_alloc(size, KM_SLEEP);
        if (p->size) {  /* overflow; mark the next entry */
                if (p->size != (size_t)-1)
                        kmem_free(p->physpath, p->size);
                ASSERT(psce->psce_out == p);
                if (p == psce->psce_last) {
                        psce->psce_first->flags |= PSC_EVENT_LOST;
                        psce->psce_out = psce->psce_first;
                } else {
                        (p + 1)->flags |= PSC_EVENT_LOST;
                        psce->psce_out = (p + 1);
                }
                overrun++;
        } else if (physpath == NULL) {  /* alloc failed, mark this entry */
                p->flags |= PSC_EVENT_LOST;
                p->size = 0;
                p->physpath = NULL;
        }
        if (which == PSC_INTEREST) {
                mutex_enter(&pm_compcnt_lock);
                if (pm_comps_notlowest == 0)
                        p->flags |= PSC_ALL_LOWEST;
                else
                        p->flags &= ~PSC_ALL_LOWEST;
                mutex_exit(&pm_compcnt_lock);
        }
        p->event = event;
        p->timestamp = gethrestime_sec();
        p->component = comp;
        p->old_level = old;
        p->new_level = new;
        p->physpath = physpath;
        p->size = size;
        if (physpath != NULL)
                (void) strcpy(p->physpath, buf);
        if (p == psce->psce_last)
                psce->psce_in = psce->psce_first;
        else
                psce->psce_in = ++p;
        mutex_exit(&psce->psce_lock);
        return (overrun);
}

/*
 * Find the next entry on the interest list.  We keep a pointer to the item we
 * last returned in the user's cooke.  Returns a locked entries struct.
 */
static psce_t *
psc_interest(void **cookie, pscc_t **psccp)
{
        pscc_t *pscc;
        pscc_t **cookiep = (pscc_t **)cookie;

        if (*cookiep == NULL)
                pscc = pm_pscc_interest;
        else
                pscc = (*cookiep)->pscc_next;
        if (pscc) {
                *cookiep = pscc;
                *psccp = pscc;
                mutex_enter(&pscc->pscc_entries->psce_lock);
                return (pscc->pscc_entries);
        } else {
                return (NULL);
        }
}

/*
 * Create an entry for a process to pick up indicating a power level change.
 */
static void
pm_enqueue_notify(ushort_t cmd, dev_info_t *dip, int comp,
    int newlevel, int oldlevel, pm_canblock_t canblock)
{
        PMD_FUNC(pmf, "enqueue_notify")
        pscc_t  *pscc;
        psce_t  *psce;
        void            *cookie = NULL;
        int     overrun;

        ASSERT(MUTEX_HELD(&pm_rsvp_lock));
        switch (cmd) {
        case PSC_PENDING_CHANGE:        /* only for controlling process */
                PMD(PMD_DPM, ("%s: PENDING %s@%s(%s#%d), comp %d, %d -> %d\n",
                    pmf, PM_DEVICE(dip), comp, oldlevel, newlevel))
                psce = pm_psc_dip_to_direct(dip, &pscc);
                ASSERT(psce);
                PMD(PMD_IOCTL, ("%s: PENDING: %s@%s(%s#%d) pm_poll_cnt[%d] "
                    "%d\n", pmf, PM_DEVICE(dip), pscc->pscc_clone,
                    pm_poll_cnt[pscc->pscc_clone]))
                overrun = psc_entry(cmd, psce, dip, comp, newlevel, oldlevel,
                    PSC_DIRECT, canblock);
                PMD(PMD_DPM, ("%s: sig %d\n", pmf, pscc->pscc_clone))
                mutex_enter(&pm_clone_lock);
                if (!overrun)
                        pm_poll_cnt[pscc->pscc_clone]++;
                cv_signal(&pm_clones_cv[pscc->pscc_clone]);
                pollwakeup(&pm_pollhead, (POLLRDNORM | POLLIN));
                mutex_exit(&pm_clone_lock);
                break;
        case PSC_HAS_CHANGED:
                PMD(PMD_DPM, ("%s: HAS %s@%s(%s#%d), comp %d, %d -> %d\n",
                    pmf, PM_DEVICE(dip), comp, oldlevel, newlevel))
                if (PM_ISDIRECT(dip) && canblock != PM_CANBLOCK_BYPASS) {
                        psce = pm_psc_dip_to_direct(dip, &pscc);
                        PMD(PMD_IOCTL, ("%s: HAS: %s@%s(%s#%d) pm_poll_cnt[%d] "
                            "%d\n", pmf, PM_DEVICE(dip), pscc->pscc_clone,
                            pm_poll_cnt[pscc->pscc_clone]))
                        overrun = psc_entry(cmd, psce, dip, comp, newlevel,
                            oldlevel, PSC_DIRECT, canblock);
                        PMD(PMD_DPM, ("%s: sig %d\n", pmf, pscc->pscc_clone))
                        mutex_enter(&pm_clone_lock);
                        if (!overrun)
                                pm_poll_cnt[pscc->pscc_clone]++;
                        cv_signal(&pm_clones_cv[pscc->pscc_clone]);
                        pollwakeup(&pm_pollhead, (POLLRDNORM | POLLIN));
                        mutex_exit(&pm_clone_lock);
                }
                mutex_enter(&pm_clone_lock);
                rw_enter(&pm_pscc_interest_rwlock, RW_READER);
                while ((psce = psc_interest(&cookie, &pscc)) != NULL) {
                        (void) psc_entry(cmd, psce, dip, comp, newlevel,
                            oldlevel, PSC_INTEREST, canblock);
                        cv_signal(&pm_clones_cv[pscc->pscc_clone]);
                }
                rw_exit(&pm_pscc_interest_rwlock);
                mutex_exit(&pm_clone_lock);
                break;
#ifdef DEBUG
        default:
                ASSERT(0);
#endif
        }
}

static void
pm_enqueue_notify_others(pm_ppm_devlist_t **listp, pm_canblock_t canblock)
{
        if (listp) {
                pm_ppm_devlist_t *p, *next = NULL;

                for (p = *listp; p; p = next) {
                        next = p->ppd_next;
                        pm_enqueue_notify(PSC_HAS_CHANGED, p->ppd_who,
                            p->ppd_cmpt, p->ppd_new_level, p->ppd_old_level,
                            canblock);
                        kmem_free(p, sizeof (pm_ppm_devlist_t));
                }
                *listp = NULL;
        }
}

/*
 * Try to get the power locks of the parent node and target (child)
 * node.  Return true if successful (with both locks held) or false
 * (with no locks held).
 */
static int
pm_try_parent_child_locks(dev_info_t *pdip,
    dev_info_t *dip, int *pcircp, int *circp)
{
        if (ndi_devi_tryenter(pdip, pcircp))
                if (PM_TRY_LOCK_POWER(dip, circp)) {
                        return (1);
                } else {
                        ndi_devi_exit(pdip, *pcircp);
                }
        return (0);
}

/*
 * Determine if the power lock owner is blocked by current thread.
 * returns :
 *      1 - If the thread owning the effective power lock (the first lock on
 *          which a thread blocks when it does PM_LOCK_POWER) is blocked by
 *          a mutex held by the current thread.
 *
 *      0 - otherwise
 *
 * Note : This function is called by pm_power_has_changed to determine whether
 * it is executing in parallel with pm_set_power.
 */
static int
pm_blocked_by_us(dev_info_t *dip)
{
        power_req_t power_req;
        kthread_t *owner;
        int result;
        kmutex_t *mp;
        dev_info_t *ppm = (dev_info_t *)DEVI(dip)->devi_pm_ppm;

        power_req.request_type = PMR_PPM_POWER_LOCK_OWNER;
        power_req.req.ppm_power_lock_owner_req.who = dip;
        if (pm_ctlops(ppm, dip, DDI_CTLOPS_POWER, &power_req, &result) !=
            DDI_SUCCESS) {
                /*
                 * It is assumed that if the device is claimed by ppm, ppm
                 * will always implement this request type and it'll always
                 * return success. We panic here, if it fails.
                 */
                panic("pm: Can't determine power lock owner of %s@%s(%s#%d)\n",
                    PM_DEVICE(dip));
                /*NOTREACHED*/
        }

        if ((owner = power_req.req.ppm_power_lock_owner_req.owner) != NULL &&
            owner->t_state == TS_SLEEP &&
            owner->t_sobj_ops &&
            SOBJ_TYPE(owner->t_sobj_ops) == SOBJ_MUTEX &&
            (mp = (kmutex_t *)owner->t_wchan) &&
            mutex_owner(mp) == curthread)
                return (1);

        return (0);
}

/*
 * Notify parent which wants to hear about a child's power changes.
 */
static void
pm_notify_parent(dev_info_t *dip,
    dev_info_t *pdip, int comp, int old_level, int level)
{
        pm_bp_has_changed_t bphc;
        pm_sp_misc_t pspm;
        char *pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        int result = DDI_SUCCESS;

        bphc.bphc_dip = dip;
        bphc.bphc_path = ddi_pathname(dip, pathbuf);
        bphc.bphc_comp = comp;
        bphc.bphc_olevel = old_level;
        bphc.bphc_nlevel = level;
        pspm.pspm_canblock = PM_CANBLOCK_BLOCK;
        pspm.pspm_scan = 0;
        bphc.bphc_private = &pspm;
        (void) (*PM_BUS_POWER_FUNC(pdip))(pdip, NULL,
            BUS_POWER_HAS_CHANGED, (void *)&bphc, (void *)&result);
        kmem_free(pathbuf, MAXPATHLEN);
}

/*
 * Check if we need to resume a BC device, and make the attach call as required.
 */
static int
pm_check_and_resume(dev_info_t *dip, int comp, int old_level, int level)
{
        int ret = DDI_SUCCESS;

        if (PM_ISBC(dip) && comp == 0 && old_level == 0 && level != 0) {
                ASSERT(DEVI(dip)->devi_pm_flags & PMC_SUSPENDED);
                /* ppm is not interested in DDI_PM_RESUME */
                if ((ret = devi_attach(dip, DDI_PM_RESUME)) != DDI_SUCCESS)
                        /* XXX Should we mark it resumed, */
                        /* even though it failed? */
                        cmn_err(CE_WARN, "!pm: Can't resume %s@%s",
                            PM_NAME(dip), PM_ADDR(dip));
                DEVI(dip)->devi_pm_flags &= ~PMC_SUSPENDED;
        }

        return (ret);
}

/*
 * Tests outside the lock to see if we should bother to enqueue an entry
 * for any watching process.  If yes, then caller will take the lock and
 * do the full protocol
 */
static int
pm_watchers()
{
        if (pm_processes_stopped)
                return (0);
        return (pm_pscc_direct || pm_pscc_interest);
}

static int pm_phc_impl(dev_info_t *, int, int, int);

/*
 * A driver is reporting that the power of one of its device's components
 * has changed.  Update the power state accordingly.
 */
int
pm_power_has_changed(dev_info_t *dip, int comp, int level)
{
        PMD_FUNC(pmf, "pm_power_has_changed")
        int ret;
        dev_info_t *pdip = ddi_get_parent(dip);
        struct pm_component *cp;
        int blocked, circ, pcirc, old_level;

        if (level < 0) {
                PMD(PMD_FAIL, ("%s: %s@%s(%s#%d): bad level=%d\n", pmf,
                    PM_DEVICE(dip), level))
                return (DDI_FAILURE);
        }

        PMD(PMD_KIDSUP | PMD_DEP, ("%s: %s@%s(%s#%d), comp=%d, level=%d\n", pmf,
            PM_DEVICE(dip), comp, level))

        if (!e_pm_valid_info(dip, NULL) || !e_pm_valid_comp(dip, comp, &cp) ||
            !e_pm_valid_power(dip, comp, level))
                return (DDI_FAILURE);

        /*
         * A driver thread calling pm_power_has_changed and another thread
         * calling pm_set_power can deadlock.  The problem is not resolvable
         * by changing lock order, so we use pm_blocked_by_us() to detect
         * this specific deadlock.  If we can't get the lock immediately
         * and we are deadlocked, just update the component's level, do
         * notifications, and return.  We intend to update the total power
         * state later (if the other thread fails to set power to the
         * desired level).  If we were called because of a power change on a
         * component that isn't involved in a set_power op, update all state
         * immediately.
         */
        cp = PM_CP(dip, comp);
        while (!pm_try_parent_child_locks(pdip, dip, &pcirc, &circ)) {
                if (((blocked = pm_blocked_by_us(dip)) != 0) &&
                    (cp->pmc_flags & PM_POWER_OP)) {
                        if (pm_watchers()) {
                                mutex_enter(&pm_rsvp_lock);
                                pm_enqueue_notify(PSC_HAS_CHANGED, dip, comp,
                                    level, cur_power(cp), PM_CANBLOCK_BLOCK);
                                mutex_exit(&pm_rsvp_lock);
                        }
                        if (pdip && PM_WANTS_NOTIFICATION(pdip))
                                pm_notify_parent(dip,
                                    pdip, comp, cur_power(cp), level);
                        (void) pm_check_and_resume(dip,
                            comp, cur_power(cp), level);

                        /*
                         * Stash the old power index, update curpwr, and flag
                         * that the total power state needs to be synched.
                         */
                        cp->pmc_flags |= PM_PHC_WHILE_SET_POWER;
                        /*
                         * Several pm_power_has_changed calls could arrive
                         * while the set power path remains blocked.  Keep the
                         * oldest old power and the newest new power of any
                         * sequence of phc calls which arrive during deadlock.
                         */
                        if (cp->pmc_phc_pwr == PM_LEVEL_UNKNOWN)
                                cp->pmc_phc_pwr = cp->pmc_cur_pwr;
                        cp->pmc_cur_pwr =
                            pm_level_to_index(dip, cp, level);
                        PMD(PMD_PHC, ("%s: deadlock for %s@%s(%s#%d), comp=%d, "
                            "level=%d\n", pmf, PM_DEVICE(dip), comp, level))
                        return (DDI_SUCCESS);
                } else
                        if (blocked) {  /* blocked, but different cmpt? */
                                if (!ndi_devi_tryenter(pdip, &pcirc)) {
                                        cmn_err(CE_NOTE,
                                            "!pm: parent kuc not updated due "
                                            "to possible deadlock.\n");
                                        return (pm_phc_impl(dip,
                                            comp, level, 1));
                                }
                                old_level = cur_power(cp);
                                if (pdip && !PM_WANTS_NOTIFICATION(pdip) &&
                                    (!PM_ISBC(dip) || comp == 0) &&
                                    POWERING_ON(old_level, level))
                                        pm_hold_power(pdip);
                                ret = pm_phc_impl(dip, comp, level, 1);
                                if (pdip && !PM_WANTS_NOTIFICATION(pdip)) {
                                        if ((!PM_ISBC(dip) ||
                                            comp == 0) && level == 0 &&
                                            old_level != PM_LEVEL_UNKNOWN)
                                                pm_rele_power(pdip);
                                }
                                ndi_devi_exit(pdip, pcirc);
                                /* child lock not held: deadlock */
                                return (ret);
                        }
                delay(1);
                PMD(PMD_PHC, ("%s: try lock again\n", pmf))
        }

        /* non-deadlock case */
        old_level = cur_power(cp);
        if (pdip && !PM_WANTS_NOTIFICATION(pdip) &&
            (!PM_ISBC(dip) || comp == 0) && POWERING_ON(old_level, level))
                pm_hold_power(pdip);
        ret = pm_phc_impl(dip, comp, level, 1);
        if (pdip && !PM_WANTS_NOTIFICATION(pdip)) {
                if ((!PM_ISBC(dip) || comp == 0) && level == 0 &&
                    old_level != PM_LEVEL_UNKNOWN)
                        pm_rele_power(pdip);
        }
        PM_UNLOCK_POWER(dip, circ);
        ndi_devi_exit(pdip, pcirc);
        return (ret);
}

/*
 * Account for power changes to a component of the the console frame buffer.
 * If lowering power from full (or "unkown", which is treatd as full)
 * we will increment the "components off" count of the fb device.
 * Subsequent lowering of the same component doesn't affect the count.  If
 * raising a component back to full power, we will decrement the count.
 *
 * Return: the increment value for pm_cfb_comps_off (-1, 0, or 1)
 */
static int
calc_cfb_comps_incr(dev_info_t *dip, int cmpt, int old, int new)
{
        struct pm_component *cp = PM_CP(dip, cmpt);
        int on = (old == PM_LEVEL_UNKNOWN || old == cp->pmc_norm_pwr);
        int want_normal = (new == cp->pmc_norm_pwr);
        int incr = 0;

        if (on && !want_normal)
                incr = 1;
        else if (!on && want_normal)
                incr = -1;
        return (incr);
}

/*
 * Adjust the count of console frame buffer components < full power.
 */
static void
update_comps_off(int incr, dev_info_t *dip)
{
                mutex_enter(&pm_cfb_lock);
                pm_cfb_comps_off += incr;
                ASSERT(pm_cfb_comps_off <= PM_NUMCMPTS(dip));
                mutex_exit(&pm_cfb_lock);
}

/*
 * Update the power state in the framework (via the ppm).  The 'notify'
 * argument tells whether to notify watchers.  Power lock is already held.
 */
static int
pm_phc_impl(dev_info_t *dip, int comp, int level, int notify)
{
        PMD_FUNC(pmf, "phc_impl")
        power_req_t power_req;
        int i, dodeps = 0;
        dev_info_t *pdip = ddi_get_parent(dip);
        int result;
        int old_level;
        struct pm_component *cp;
        int incr = 0;
        dev_info_t *ppm = (dev_info_t *)DEVI(dip)->devi_pm_ppm;
        int work_type = 0;
        char *pathbuf;

        /* Must use "official" power level for this test. */
        cp = PM_CP(dip, comp);
        old_level = (cp->pmc_flags & PM_PHC_WHILE_SET_POWER ?
            cp->pmc_phc_pwr : cp->pmc_cur_pwr);
        if (old_level != PM_LEVEL_UNKNOWN)
                old_level = cp->pmc_comp.pmc_lvals[old_level];

        if (level == old_level) {
                PMD(PMD_SET, ("%s: %s@%s(%s#%d), comp=%d is already at "
                    "level=%d\n", pmf, PM_DEVICE(dip), comp, level))
                return (DDI_SUCCESS);
        }

        /*
         * Tell ppm about this.
         */
        power_req.request_type = PMR_PPM_POWER_CHANGE_NOTIFY;
        power_req.req.ppm_notify_level_req.who = dip;
        power_req.req.ppm_notify_level_req.cmpt = comp;
        power_req.req.ppm_notify_level_req.new_level = level;
        power_req.req.ppm_notify_level_req.old_level = old_level;
        if (pm_ctlops(ppm, dip, DDI_CTLOPS_POWER, &power_req,
            &result) == DDI_FAILURE) {
                PMD(PMD_FAIL, ("%s: pm_ctlops %s@%s(%s#%d) to %d failed\n",
                    pmf, PM_DEVICE(dip), level))
                return (DDI_FAILURE);
        }

        if (PM_IS_CFB(dip)) {
                incr = calc_cfb_comps_incr(dip, comp, old_level, level);

                if (incr) {
                        update_comps_off(incr, dip);
                        PMD(PMD_CFB, ("%s: %s@%s(%s#%d) comp=%d %d->%d "
                            "cfb_comps_off->%d\n", pmf, PM_DEVICE(dip),
                            comp, old_level, level, pm_cfb_comps_off))
                }
        }
        e_pm_set_cur_pwr(dip, PM_CP(dip, comp), level);
        result = DDI_SUCCESS;

        if (notify) {
                if (pdip && PM_WANTS_NOTIFICATION(pdip))
                        pm_notify_parent(dip, pdip, comp, old_level, level);
                (void) pm_check_and_resume(dip, comp, old_level, level);
        }

        /*
         * Decrement the dependency kidsup count if we turn a device
         * off.
         */
        if (POWERING_OFF(old_level, level)) {
                dodeps = 1;
                for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                        cp = PM_CP(dip, i);
                        if (cur_power(cp)) {
                                dodeps = 0;
                                break;
                        }
                }
                if (dodeps)
                        work_type = PM_DEP_WK_POWER_OFF;
        }

        /*
         * Increment if we turn it on. Check to see
         * if other comps are already on, if so,
         * dont increment.
         */
        if (POWERING_ON(old_level, level)) {
                dodeps = 1;
                for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                        cp = PM_CP(dip, i);
                        if (comp == i)
                                continue;
                        /* -1 also treated as 0 in this case */
                        if (cur_power(cp) > 0) {
                                dodeps = 0;
                                break;
                        }
                }
                if (dodeps)
                        work_type = PM_DEP_WK_POWER_ON;
        }

        if (dodeps) {
                pathbuf = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
                (void) ddi_pathname(dip, pathbuf);
                pm_dispatch_to_dep_thread(work_type, pathbuf, NULL,
                    PM_DEP_NOWAIT, NULL, 0);
                kmem_free(pathbuf, MAXPATHLEN);
        }

        if (notify && (level != old_level) && pm_watchers()) {
                mutex_enter(&pm_rsvp_lock);
                pm_enqueue_notify(PSC_HAS_CHANGED, dip, comp, level, old_level,
                    PM_CANBLOCK_BLOCK);
                mutex_exit(&pm_rsvp_lock);
        }

        PMD(PMD_RESCAN, ("%s: %s@%s(%s#%d): pm_rescan\n", pmf, PM_DEVICE(dip)))
        pm_rescan(dip);
        return (DDI_SUCCESS);
}

/*
 * This function is called at startup time to notify pm of the existence
 * of any platform power managers for this platform.  As a result of
 * this registration, each function provided will be called each time
 * a device node is attached, until one returns true, and it must claim the
 * device node (by returning non-zero) if it wants to be involved in the
 * node's power management.  If it does claim the node, then it will
 * subsequently be notified of attach and detach events.
 *
 */

int
pm_register_ppm(int (*func)(dev_info_t *), dev_info_t *dip)
{
        PMD_FUNC(pmf, "register_ppm")
        struct ppm_callbacks *ppmcp;
        pm_component_t *cp;
        int i, pwr, result, circ;
        power_req_t power_req;
        struct ppm_notify_level_req *p = &power_req.req.ppm_notify_level_req;
        void pm_ppm_claim(dev_info_t *);

        mutex_enter(&ppm_lock);
        ppmcp = ppm_callbacks;
        for (i = 0; i < MAX_PPM_HANDLERS; i++, ppmcp++) {
                if (ppmcp->ppmc_func == NULL) {
                        ppmcp->ppmc_func = func;
                        ppmcp->ppmc_dip = dip;
                        break;
                }
        }
        mutex_exit(&ppm_lock);

        if (i >= MAX_PPM_HANDLERS)
                return (DDI_FAILURE);
        while ((dip = ddi_get_parent(dip)) != NULL) {
                if (dip != ddi_root_node() && PM_GET_PM_INFO(dip) == NULL)
                        continue;
                pm_ppm_claim(dip);
                /* don't bother with the not power-manageable nodes */
                if (pm_ppm_claimed(dip) && PM_GET_PM_INFO(dip)) {
                        /*
                         * Tell ppm about this.
                         */
                        power_req.request_type = PMR_PPM_POWER_CHANGE_NOTIFY;
                        p->old_level = PM_LEVEL_UNKNOWN;
                        p->who = dip;
                        PM_LOCK_POWER(dip, &circ);
                        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                                cp = PM_CP(dip, i);
                                pwr = cp->pmc_cur_pwr;
                                if (pwr != PM_LEVEL_UNKNOWN) {
                                        p->cmpt = i;
                                        p->new_level = cur_power(cp);
                                        p->old_level = PM_LEVEL_UNKNOWN;
                                        if (pm_ctlops(PPM(dip), dip,
                                            DDI_CTLOPS_POWER, &power_req,
                                            &result) == DDI_FAILURE) {
                                                PMD(PMD_FAIL, ("%s: pc "
                                                    "%s@%s(%s#%d) to %d "
                                                    "fails\n", pmf,
                                                    PM_DEVICE(dip), pwr))
                                        }
                                }
                        }
                        PM_UNLOCK_POWER(dip, circ);
                }
        }
        return (DDI_SUCCESS);
}

/*
 * Call the ppm's that have registered and adjust the devinfo struct as
 * appropriate.  First one to claim it gets it.  The sets of devices claimed
 * by each ppm are assumed to be disjoint.
 */
void
pm_ppm_claim(dev_info_t *dip)
{
        struct ppm_callbacks *ppmcp;

        if (PPM(dip)) {
                return;
        }
        mutex_enter(&ppm_lock);
        for (ppmcp = ppm_callbacks; ppmcp->ppmc_func; ppmcp++) {
                if ((*ppmcp->ppmc_func)(dip)) {
                        DEVI(dip)->devi_pm_ppm =
                            (struct dev_info *)ppmcp->ppmc_dip;
                        mutex_exit(&ppm_lock);
                        return;
                }
        }
        mutex_exit(&ppm_lock);
}

/*
 * Node is being detached so stop autopm until we see if it succeeds, in which
 * case pm_stop will be called.  For backwards compatible devices we bring the
 * device up to full power on the assumption the detach will succeed.
 */
void
pm_detaching(dev_info_t *dip)
{
        PMD_FUNC(pmf, "detaching")
        pm_info_t *info = PM_GET_PM_INFO(dip);
        int iscons;

        PMD(PMD_REMDEV, ("%s: %s@%s(%s#%d), %d comps\n", pmf, PM_DEVICE(dip),
            PM_NUMCMPTS(dip)))
        if (info == NULL)
                return;
        ASSERT(DEVI_IS_DETACHING(dip));
        PM_LOCK_DIP(dip);
        info->pmi_dev_pm_state |= PM_DETACHING;
        PM_UNLOCK_DIP(dip);
        if (!PM_ISBC(dip))
                pm_scan_stop(dip);

        /*
         * console and old-style devices get brought up when detaching.
         */
        iscons = PM_IS_CFB(dip);
        if (iscons || PM_ISBC(dip)) {
                (void) pm_all_to_normal(dip, PM_CANBLOCK_BYPASS);
                if (iscons) {
                        mutex_enter(&pm_cfb_lock);
                        while (cfb_inuse) {
                                mutex_exit(&pm_cfb_lock);
                                PMD(PMD_CFB, ("%s: delay; cfb_inuse\n", pmf))
                                delay(1);
                                mutex_enter(&pm_cfb_lock);
                        }
                        ASSERT(cfb_dip_detaching == NULL);
                        ASSERT(cfb_dip);
                        cfb_dip_detaching = cfb_dip;    /* case detach fails */
                        cfb_dip = NULL;
                        mutex_exit(&pm_cfb_lock);
                }
        }
}

/*
 * Node failed to detach.  If it used to be autopm'd, make it so again.
 */
void
pm_detach_failed(dev_info_t *dip)
{
        PMD_FUNC(pmf, "detach_failed")
        pm_info_t *info = PM_GET_PM_INFO(dip);
        int pm_all_at_normal(dev_info_t *);

        if (info == NULL)
                return;
        ASSERT(DEVI_IS_DETACHING(dip));
        if (info->pmi_dev_pm_state & PM_DETACHING) {
                info->pmi_dev_pm_state &= ~PM_DETACHING;
                if (info->pmi_dev_pm_state & PM_ALLNORM_DEFERRED) {
                        /* Make sure the operation is still needed */
                        if (!pm_all_at_normal(dip)) {
                                if (pm_all_to_normal(dip,
                                    PM_CANBLOCK_FAIL) != DDI_SUCCESS) {
                                        PMD(PMD_ERROR, ("%s: could not bring "
                                            "%s@%s(%s#%d) to normal\n", pmf,
                                            PM_DEVICE(dip)))
                                }
                        }
                        info->pmi_dev_pm_state &= ~PM_ALLNORM_DEFERRED;
                }
        }
        if (!PM_ISBC(dip)) {
                mutex_enter(&pm_scan_lock);
                if (PM_SCANABLE(dip))
                        pm_scan_init(dip);
                mutex_exit(&pm_scan_lock);
                pm_rescan(dip);
        }
}

/* generic Backwards Compatible component */
static char *bc_names[] = {"off", "on"};

static pm_comp_t bc_comp = {"unknown", 2, NULL, NULL, &bc_names[0]};

static void
e_pm_default_levels(dev_info_t *dip, pm_component_t *cp, int norm)
{
        pm_comp_t *pmc;
        pmc = &cp->pmc_comp;
        pmc->pmc_numlevels = 2;
        pmc->pmc_lvals[0] = 0;
        pmc->pmc_lvals[1] = norm;
        e_pm_set_cur_pwr(dip, cp, norm);
}

static void
e_pm_default_components(dev_info_t *dip, int cmpts)
{
        int i;
        pm_component_t *p = DEVI(dip)->devi_pm_components;

        p = DEVI(dip)->devi_pm_components;
        for (i = 0; i < cmpts; i++, p++) {
                p->pmc_comp = bc_comp;  /* struct assignment */
                p->pmc_comp.pmc_lvals = kmem_zalloc(2 * sizeof (int),
                    KM_SLEEP);
                p->pmc_comp.pmc_thresh = kmem_alloc(2 * sizeof (int),
                    KM_SLEEP);
                p->pmc_comp.pmc_numlevels = 2;
                p->pmc_comp.pmc_thresh[0] = INT_MAX;
                p->pmc_comp.pmc_thresh[1] = INT_MAX;
        }
}

/*
 * Called from functions that require components to exist already to allow
 * for their creation by parsing the pm-components property.
 * Device will not be power managed as a result of this call
 * No locking needed because we're single threaded by the ndi_devi_enter
 * done while attaching, and the device isn't visible until after it has
 * attached
 */
int
pm_premanage(dev_info_t *dip, int style)
{
        PMD_FUNC(pmf, "premanage")
        pm_comp_t       *pcp, *compp;
        int             cmpts, i, norm, error;
        pm_component_t *p = DEVI(dip)->devi_pm_components;
        pm_comp_t *pm_autoconfig(dev_info_t *, int *);

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        /*
         * If this dip has already been processed, don't mess with it
         */
        if (DEVI(dip)->devi_pm_flags & PMC_COMPONENTS_DONE)
                return (DDI_SUCCESS);
        if (DEVI(dip)->devi_pm_flags & PMC_COMPONENTS_FAILED) {
                return (DDI_FAILURE);
        }
        /*
         * Look up pm-components property and create components accordingly
         * If that fails, fall back to backwards compatibility
         */
        if ((compp = pm_autoconfig(dip, &error)) == NULL) {
                /*
                 * If error is set, the property existed but was not well formed
                 */
                if (error || (style == PM_STYLE_NEW)) {
                        DEVI(dip)->devi_pm_flags |= PMC_COMPONENTS_FAILED;
                        return (DDI_FAILURE);
                }
                /*
                 * If they don't have the pm-components property, then we
                 * want the old "no pm until PM_SET_DEVICE_THRESHOLDS ioctl"
                 * behavior driver must have called pm_create_components, and
                 * we need to flesh out dummy components
                 */
                if ((cmpts = PM_NUMCMPTS(dip)) == 0) {
                        /*
                         * Not really failure, but we don't want the
                         * caller to treat it as success
                         */
                        return (DDI_FAILURE);
                }
                DEVI(dip)->devi_pm_flags |= PMC_BC;
                e_pm_default_components(dip, cmpts);
                for (i = 0; i < cmpts; i++) {
                        /*
                         * if normal power not set yet, we don't really know
                         * what *ANY* of the power values are.  If normal
                         * power is set, then we assume for this backwards
                         * compatible case that the values are 0, normal power.
                         */
                        norm = pm_get_normal_power(dip, i);
                        if (norm == (uint_t)-1) {
                                PMD(PMD_ERROR, ("%s: %s@%s(%s#%d)[%d]\n", pmf,
                                    PM_DEVICE(dip), i))
                                return (DDI_FAILURE);
                        }
                        /*
                         * Components of BC devices start at their normal power,
                         * so count them to be not at their lowest power.
                         */
                        PM_INCR_NOTLOWEST(dip);
                        e_pm_default_levels(dip, PM_CP(dip, i), norm);
                }
        } else {
                /*
                 * e_pm_create_components was called from pm_autoconfig(), it
                 * creates components with no descriptions (or known levels)
                 */
                cmpts = PM_NUMCMPTS(dip);
                ASSERT(cmpts != 0);
                pcp = compp;
                p = DEVI(dip)->devi_pm_components;
                for (i = 0; i < cmpts; i++, p++) {
                        p->pmc_comp = *pcp++;   /* struct assignment */
                        ASSERT(PM_CP(dip, i)->pmc_cur_pwr == 0);
                        e_pm_set_cur_pwr(dip, PM_CP(dip, i), PM_LEVEL_UNKNOWN);
                }
                if (DEVI(dip)->devi_pm_flags & PMC_CPU_THRESH)
                        pm_set_device_threshold(dip, pm_cpu_idle_threshold,
                            PMC_CPU_THRESH);
                else
                        pm_set_device_threshold(dip, pm_system_idle_threshold,
                            PMC_DEF_THRESH);
                kmem_free(compp, cmpts * sizeof (pm_comp_t));
        }
        return (DDI_SUCCESS);
}

/*
 * Called from during or after the device's attach to let us know it is ready
 * to play autopm.   Look up the pm model and manage the device accordingly.
 * Returns system call errno value.
 * If DDI_ATTACH and DDI_DETACH were in same namespace, this would be
 * a little cleaner
 *
 * Called with dip lock held, return with dip lock unheld.
 */

int
e_pm_manage(dev_info_t *dip, int style)
{
        PMD_FUNC(pmf, "e_manage")
        pm_info_t       *info;
        dev_info_t      *pdip = ddi_get_parent(dip);
        int     pm_thresh_specd(dev_info_t *);
        int     count;
        char    *pathbuf;

        if (pm_premanage(dip, style) != DDI_SUCCESS) {
                return (DDI_FAILURE);
        }
        PMD(PMD_KIDSUP, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        ASSERT(PM_GET_PM_INFO(dip) == NULL);
        info = kmem_zalloc(sizeof (pm_info_t), KM_SLEEP);

        /*
         * Now set up parent's kidsupcnt.  BC nodes are assumed to start
         * out at their normal power, so they are "up", others start out
         * unknown, which is effectively "up".  Parent which want notification
         * get kidsupcnt of 0 always.
         */
        count = (PM_ISBC(dip)) ? 1 : PM_NUMCMPTS(dip);
        if (count && pdip && !PM_WANTS_NOTIFICATION(pdip))
                e_pm_hold_rele_power(pdip, count);

        pm_set_pm_info(dip, info);
        /*
         * Apply any recorded thresholds
         */
        (void) pm_thresh_specd(dip);

        /*
         * Do dependency processing.
         */
        pathbuf = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);
        pm_dispatch_to_dep_thread(PM_DEP_WK_ATTACH, pathbuf, pathbuf,
            PM_DEP_NOWAIT, NULL, 0);
        kmem_free(pathbuf, MAXPATHLEN);

        if (!PM_ISBC(dip)) {
                mutex_enter(&pm_scan_lock);
                if (PM_SCANABLE(dip)) {
                        pm_scan_init(dip);
                        mutex_exit(&pm_scan_lock);
                        pm_rescan(dip);
                } else {
                        mutex_exit(&pm_scan_lock);
                }
        }
        return (0);
}

/*
 * This is the obsolete exported interface for a driver to find out its
 * "normal" (max) power.
 * We only get components destroyed while no power management is
 * going on (and the device is detached), so we don't need a mutex here
 */
int
pm_get_normal_power(dev_info_t *dip, int comp)
{

        if (comp >= 0 && comp < PM_NUMCMPTS(dip)) {
                return (PM_CP(dip, comp)->pmc_norm_pwr);
        }
        return (DDI_FAILURE);
}

/*
 * Fetches the current power level.  Return DDI_SUCCESS or DDI_FAILURE.
 */
int
pm_get_current_power(dev_info_t *dip, int comp, int *levelp)
{
        if (comp >= 0 && comp < PM_NUMCMPTS(dip)) {
                *levelp = PM_CURPOWER(dip, comp);
                return (DDI_SUCCESS);
        }
        return (DDI_FAILURE);
}

/*
 * Returns current threshold of indicated component
 */
static int
cur_threshold(dev_info_t *dip, int comp)
{
        pm_component_t *cp = PM_CP(dip, comp);
        int pwr;

        if (PM_ISBC(dip)) {
                /*
                 * backwards compatible nodes only have one threshold
                 */
                return (cp->pmc_comp.pmc_thresh[1]);
        }
        pwr = cp->pmc_cur_pwr;
        if (pwr == PM_LEVEL_UNKNOWN) {
                int thresh;
                if (DEVI(dip)->devi_pm_flags & PMC_NEXDEF_THRESH)
                        thresh = pm_default_nexus_threshold;
                else if (DEVI(dip)->devi_pm_flags & PMC_CPU_THRESH)
                        thresh = pm_cpu_idle_threshold;
                else
                        thresh = pm_system_idle_threshold;
                return (thresh);
        }
        ASSERT(cp->pmc_comp.pmc_thresh);
        return (cp->pmc_comp.pmc_thresh[pwr]);
}

/*
 * Compute next lower component power level given power index.
 */
static int
pm_next_lower_power(pm_component_t *cp, int pwrndx)
{
        int nxt_pwr;

        if (pwrndx == PM_LEVEL_UNKNOWN) {
                nxt_pwr = cp->pmc_comp.pmc_lvals[0];
        } else {
                pwrndx--;
                ASSERT(pwrndx >= 0);
                nxt_pwr = cp->pmc_comp.pmc_lvals[pwrndx];
        }
        return (nxt_pwr);
}

/*
 * Update the maxpower (normal) power of a component. Note that the
 * component's power level is only changed if it's current power level
 * is higher than the new max power.
 */
int
pm_update_maxpower(dev_info_t *dip, int comp, int level)
{
        PMD_FUNC(pmf, "update_maxpower")
        int old;
        int result;

        if (!e_pm_valid_info(dip, NULL) || !e_pm_valid_comp(dip, comp, NULL) ||
            !e_pm_valid_power(dip, comp, level)) {
                PMD(PMD_FAIL, ("%s: validation checks failed for %s@%s(%s#%d) "
                    "comp=%d level=%d\n", pmf, PM_DEVICE(dip), comp, level))
                return (DDI_FAILURE);
        }
        old = e_pm_get_max_power(dip, comp);
        e_pm_set_max_power(dip, comp, level);

        if (pm_set_power(dip, comp, level, PM_LEVEL_DOWNONLY,
            PM_CANBLOCK_BLOCK, 0, &result) != DDI_SUCCESS) {
                e_pm_set_max_power(dip, comp, old);
                PMD(PMD_FAIL, ("%s: %s@%s(%s#%d) pm_set_power failed\n", pmf,
                    PM_DEVICE(dip)))
                return (DDI_FAILURE);
        }
        return (DDI_SUCCESS);
}

/*
 * Bring all components of device to normal power
 */
int
pm_all_to_normal(dev_info_t *dip, pm_canblock_t canblock)
{
        PMD_FUNC(pmf, "all_to_normal")
        int             *normal;
        int             i, ncomps, result;
        size_t          size;
        int             changefailed = 0;

        PMD(PMD_ALLNORM, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        ASSERT(PM_GET_PM_INFO(dip));
        if (pm_get_norm_pwrs(dip, &normal, &size) != DDI_SUCCESS) {
                PMD(PMD_ALLNORM, ("%s: can't get norm pwrs for "
                    "%s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
                return (DDI_FAILURE);
        }
        ncomps = PM_NUMCMPTS(dip);
        for (i = 0; i < ncomps; i++) {
                if (pm_set_power(dip, i, normal[i],
                    PM_LEVEL_UPONLY, canblock, 0, &result) != DDI_SUCCESS) {
                        changefailed++;
                        PMD(PMD_ALLNORM | PMD_FAIL, ("%s: failed to set "
                            "%s@%s(%s#%d)[%d] to %d, errno %d\n", pmf,
                            PM_DEVICE(dip), i, normal[i], result))
                }
        }
        kmem_free(normal, size);
        if (changefailed) {
                PMD(PMD_FAIL, ("%s: failed to set %d comps %s@%s(%s#%d) "
                    "to full power\n", pmf, changefailed, PM_DEVICE(dip)))
                return (DDI_FAILURE);
        }
        return (DDI_SUCCESS);
}

/*
 * Returns true if all components of device are at normal power
 */
int
pm_all_at_normal(dev_info_t *dip)
{
        PMD_FUNC(pmf, "all_at_normal")
        int             *normal;
        int             i;
        size_t          size;

        PMD(PMD_ALLNORM, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        if (pm_get_norm_pwrs(dip, &normal, &size) != DDI_SUCCESS) {
                PMD(PMD_ALLNORM, ("%s: can't get normal power\n", pmf))
                return (DDI_FAILURE);
        }
        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                int current = PM_CURPOWER(dip, i);
                if (normal[i] > current) {
                        PMD(PMD_ALLNORM, ("%s: %s@%s(%s#%d) comp=%d, "
                            "norm=%d, cur=%d\n", pmf, PM_DEVICE(dip), i,
                            normal[i], current))
                        break;
                }
        }
        kmem_free(normal, size);
        if (i != PM_NUMCMPTS(dip)) {
                return (0);
        }
        return (1);
}

static void bring_pmdep_up(dev_info_t *, int);

static void
bring_wekeeps_up(char *keeper)
{
        PMD_FUNC(pmf, "bring_wekeeps_up")
        int i;
        pm_pdr_t *dp;
        pm_info_t *wku_info;
        char *kept_path;
        dev_info_t *kept;

        if (panicstr) {
                return;
        }
        /*
         * We process the request even if the keeper detaches because
         * detach processing expects this to increment kidsupcnt of kept.
         */
        PMD(PMD_BRING, ("%s: keeper= %s\n", pmf, keeper))
        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (strcmp(dp->pdr_keeper, keeper) != 0)
                        continue;
                for (i = 0; i < dp->pdr_kept_count; i++) {
                        kept_path = dp->pdr_kept_paths[i];
                        if (kept_path == NULL)
                                continue;
                        ASSERT(kept_path[0] != '\0');
                        if ((kept = pm_name_to_dip(kept_path, 1)) == NULL)
                                continue;
                        wku_info = PM_GET_PM_INFO(kept);
                        if (wku_info == NULL) {
                                if (kept)
                                        ddi_release_devi(kept);
                                continue;
                        }
                        /*
                         * Don't mess with it if it is being detached, it isn't
                         * safe to call its power entry point
                         */
                        if (wku_info->pmi_dev_pm_state & PM_DETACHING) {
                                if (kept)
                                        ddi_release_devi(kept);
                                continue;
                        }
                        bring_pmdep_up(kept, 1);
                        ddi_release_devi(kept);
                }
        }
}

/*
 * Bring up the 'kept' device passed as argument
 */
static void
bring_pmdep_up(dev_info_t *kept_dip, int hold)
{
        PMD_FUNC(pmf, "bring_pmdep_up")
        int is_all_at_normal = 0;

        /*
         * If the kept device has been unmanaged, do nothing.
         */
        if (!PM_GET_PM_INFO(kept_dip))
                return;

        /* Just ignore DIRECT PM device till they are released. */
        if (!pm_processes_stopped && PM_ISDIRECT(kept_dip) &&
            !(is_all_at_normal = pm_all_at_normal(kept_dip))) {
                PMD(PMD_BRING, ("%s: can't bring up PM_DIRECT %s@%s(%s#%d) "
                    "controlling process did something else\n", pmf,
                    PM_DEVICE(kept_dip)))
                DEVI(kept_dip)->devi_pm_flags |= PMC_SKIP_BRINGUP;
                return;
        }
        /* if we got here the keeper had a transition from OFF->ON */
        if (hold)
                pm_hold_power(kept_dip);

        if (!is_all_at_normal)
                (void) pm_all_to_normal(kept_dip, PM_CANBLOCK_FAIL);
}

/*
 * A bunch of stuff that belongs only to the next routine (or two)
 */

static const char namestr[] = "NAME=";
static const int nameln = sizeof (namestr) - 1;
static const char pmcompstr[] = "pm-components";

struct pm_comp_pkg {
        pm_comp_t               *comp;
        struct pm_comp_pkg      *next;
};

#define isdigit(ch)     ((ch) >= '0' && (ch) <= '9')

#define isxdigit(ch)    (isdigit(ch) || ((ch) >= 'a' && (ch) <= 'f') || \
                        ((ch) >= 'A' && (ch) <= 'F'))

/*
 * Rather than duplicate this code ...
 * (this code excerpted from the function that follows it)
 */
#define FINISH_COMP { \
        ASSERT(compp); \
        compp->pmc_lnames_sz = size; \
        tp = compp->pmc_lname_buf = kmem_alloc(size, KM_SLEEP); \
        compp->pmc_numlevels = level; \
        compp->pmc_lnames = kmem_alloc(level * sizeof (char *), KM_SLEEP); \
        compp->pmc_lvals = kmem_alloc(level * sizeof (int), KM_SLEEP); \
        compp->pmc_thresh = kmem_alloc(level * sizeof (int), KM_SLEEP); \
        /* copy string out of prop array into buffer */ \
        for (j = 0; j < level; j++) { \
                compp->pmc_thresh[j] = INT_MAX;         /* only [0] sticks */ \
                compp->pmc_lvals[j] = lvals[j]; \
                (void) strcpy(tp, lnames[j]); \
                compp->pmc_lnames[j] = tp; \
                tp += lszs[j]; \
        } \
        ASSERT(tp > compp->pmc_lname_buf && tp <= \
            compp->pmc_lname_buf + compp->pmc_lnames_sz); \
        }

/*
 * Create (empty) component data structures.
 */
static void
e_pm_create_components(dev_info_t *dip, int num_components)
{
        struct pm_component *compp, *ocompp;
        int i, size = 0;

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        ASSERT(!DEVI(dip)->devi_pm_components);
        ASSERT(!(DEVI(dip)->devi_pm_flags & PMC_COMPONENTS_DONE));
        size = sizeof (struct pm_component) * num_components;

        compp = kmem_zalloc(size, KM_SLEEP);
        ocompp = compp;
        DEVI(dip)->devi_pm_comp_size = size;
        DEVI(dip)->devi_pm_num_components = num_components;
        PM_LOCK_BUSY(dip);
        for (i = 0; i < num_components;  i++) {
                compp->pmc_timestamp = gethrestime_sec();
                compp->pmc_norm_pwr = (uint_t)-1;
                compp++;
        }
        PM_UNLOCK_BUSY(dip);
        DEVI(dip)->devi_pm_components = ocompp;
        DEVI(dip)->devi_pm_flags |= PMC_COMPONENTS_DONE;
}

/*
 * Parse hex or decimal value from char string
 */
static char *
pm_parsenum(char *cp, int *valp)
{
        int ch, offset;
        char numbuf[256];
        char *np = numbuf;
        int value = 0;

        ch = *cp++;
        if (isdigit(ch)) {
                if (ch == '0') {
                        if ((ch = *cp++) == 'x' || ch == 'X') {
                                ch = *cp++;
                                while (isxdigit(ch)) {
                                        *np++ = (char)ch;
                                        ch = *cp++;
                                }
                                *np = 0;
                                cp--;
                                goto hexval;
                        } else {
                                goto digit;
                        }
                } else {
digit:
                        while (isdigit(ch)) {
                                *np++ = (char)ch;
                                ch = *cp++;
                        }
                        *np = 0;
                        cp--;
                        goto decval;
                }
        } else
                return (NULL);

hexval:
        for (np = numbuf; *np; np++) {
                if (*np >= 'a' && *np <= 'f')
                        offset = 'a' - 10;
                else if (*np >= 'A' && *np <= 'F')
                        offset = 'A' - 10;
                else if (*np >= '0' && *np <= '9')
                        offset = '0';
                value *= 16;
                value += *np - offset;
        }
        *valp = value;
        return (cp);

decval:
        offset = '0';
        for (np = numbuf; *np; np++) {
                value *= 10;
                value += *np - offset;
        }
        *valp = value;
        return (cp);
}

/*
 * Set max (previously documented as "normal") power.
 */
static void
e_pm_set_max_power(dev_info_t *dip, int component_number, int level)
{
        PM_CP(dip, component_number)->pmc_norm_pwr = level;
}

/*
 * Get max (previously documented as "normal") power.
 */
static int
e_pm_get_max_power(dev_info_t *dip, int component_number)
{
        return (PM_CP(dip, component_number)->pmc_norm_pwr);
}

/*
 * Internal routine for destroying components
 * It is called even when there might not be any, so it must be forgiving.
 */
static void
e_pm_destroy_components(dev_info_t *dip)
{
        int i;
        struct pm_component *cp;

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        if (PM_NUMCMPTS(dip) == 0)
                return;
        cp = DEVI(dip)->devi_pm_components;
        ASSERT(cp);
        for (i = 0; i < PM_NUMCMPTS(dip); i++, cp++) {
                int nlevels = cp->pmc_comp.pmc_numlevels;
                kmem_free(cp->pmc_comp.pmc_lvals, nlevels * sizeof (int));
                kmem_free(cp->pmc_comp.pmc_thresh, nlevels * sizeof (int));
                /*
                 * For BC nodes, the rest is static in bc_comp, so skip it
                 */
                if (PM_ISBC(dip))
                        continue;
                kmem_free(cp->pmc_comp.pmc_name, cp->pmc_comp.pmc_name_sz);
                kmem_free(cp->pmc_comp.pmc_lnames, nlevels * sizeof (char *));
                kmem_free(cp->pmc_comp.pmc_lname_buf,
                    cp->pmc_comp.pmc_lnames_sz);
        }
        kmem_free(DEVI(dip)->devi_pm_components, DEVI(dip)->devi_pm_comp_size);
        DEVI(dip)->devi_pm_components = NULL;
        DEVI(dip)->devi_pm_num_components = 0;
        DEVI(dip)->devi_pm_flags &=
            ~(PMC_COMPONENTS_DONE | PMC_COMPONENTS_FAILED);
}

/*
 * Read the pm-components property (if there is one) and use it to set up
 * components.  Returns a pointer to an array of component structures if
 * pm-components found and successfully parsed, else returns NULL.
 * Sets error return *errp to true to indicate a failure (as opposed to no
 * property being present).
 */
pm_comp_t *
pm_autoconfig(dev_info_t *dip, int *errp)
{
        PMD_FUNC(pmf, "autoconfig")
        uint_t nelems;
        char **pp;
        pm_comp_t *compp = NULL;
        int i, j, level, components = 0;
        size_t size = 0;
        struct pm_comp_pkg *p, *ptail;
        struct pm_comp_pkg *phead = NULL;
        int *lvals = NULL;
        int *lszs = NULL;
        int *np = NULL;
        int npi = 0;
        char **lnames = NULL;
        char *cp, *tp;
        pm_comp_t *ret = NULL;

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        *errp = 0;      /* assume success */
        if (ddi_prop_lookup_string_array(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS,
            (char *)pmcompstr, &pp, &nelems) != DDI_PROP_SUCCESS) {
                return (NULL);
        }

        if (nelems < 3) {       /* need at least one name and two levels */
                goto errout;
        }

        /*
         * pm_create_components is no longer allowed
         */
        if (PM_NUMCMPTS(dip) != 0) {
                PMD(PMD_ERROR, ("%s: %s@%s(%s#%d) has %d comps\n",
                    pmf, PM_DEVICE(dip), PM_NUMCMPTS(dip)))
                goto errout;
        }

        lvals = kmem_alloc(nelems * sizeof (int), KM_SLEEP);
        lszs = kmem_alloc(nelems * sizeof (int), KM_SLEEP);
        lnames = kmem_alloc(nelems * sizeof (char *), KM_SLEEP);
        np = kmem_alloc(nelems * sizeof (int), KM_SLEEP);

        level = 0;
        phead = NULL;
        for (i = 0; i < nelems; i++) {
                cp = pp[i];
                if (!isdigit(*cp)) {    /*  must be name */
                        if (strncmp(cp, namestr, nameln) != 0) {
                                goto errout;
                        }
                        if (i != 0) {
                                if (level == 0) {       /* no level spec'd */
                                        PMD(PMD_ERROR, ("%s: no level spec'd\n",
                                            pmf))
                                        goto errout;
                                }
                                np[npi++] = lvals[level - 1];
                                /* finish up previous component levels */
                                FINISH_COMP;
                        }
                        cp += nameln;
                        if (!*cp) {
                                PMD(PMD_ERROR, ("%s: nsa\n", pmf))
                                goto errout;
                        }
                        p = kmem_zalloc(sizeof (*phead), KM_SLEEP);
                        if (phead == NULL) {
                                phead = ptail = p;
                        } else {
                                ptail->next = p;
                                ptail = p;
                        }
                        compp = p->comp = kmem_zalloc(sizeof (pm_comp_t),
                            KM_SLEEP);
                        compp->pmc_name_sz = strlen(cp) + 1;
                        compp->pmc_name = kmem_zalloc(compp->pmc_name_sz,
                            KM_SLEEP);
                        (void) strncpy(compp->pmc_name, cp, compp->pmc_name_sz);
                        components++;
                        level = 0;
                } else {        /* better be power level <num>=<name> */
#ifdef DEBUG
                        tp = cp;
#endif
                        if (i == 0 ||
                            (cp = pm_parsenum(cp, &lvals[level])) == NULL) {
                                PMD(PMD_ERROR, ("%s: parsenum(%s)\n", pmf, tp))
                                goto errout;
                        }
#ifdef DEBUG
                        tp = cp;
#endif
                        if (*cp++ != '=' || !*cp) {
                                PMD(PMD_ERROR, ("%s: ex =, got %s\n", pmf, tp))
                                goto errout;
                        }

                        lszs[level] = strlen(cp) + 1;
                        size += lszs[level];
                        lnames[level] = cp;     /* points into prop string */
                        level++;
                }
        }
        np[npi++] = lvals[level - 1];
        if (level == 0) {       /* ended with a name */
                PMD(PMD_ERROR, ("%s: ewn\n", pmf))
                goto errout;
        }
        FINISH_COMP;


        /*
         * Now we have a list of components--we have to return instead an
         * array of them, but we can just copy the top level and leave
         * the rest as is
         */
        (void) e_pm_create_components(dip, components);
        for (i = 0; i < components; i++)
                e_pm_set_max_power(dip, i, np[i]);

        ret = kmem_zalloc(components * sizeof (pm_comp_t), KM_SLEEP);
        for (i = 0, p = phead; i < components; i++) {
                ASSERT(p);
                /*
                 * Now sanity-check values:  levels must be monotonically
                 * increasing
                 */
                if (p->comp->pmc_numlevels < 2) {
                        PMD(PMD_ERROR, ("%s: comp %s of %s@%s(%s#%d) only %d "
                            "levels\n", pmf,
                            p->comp->pmc_name, PM_DEVICE(dip),
                            p->comp->pmc_numlevels))
                        goto errout;
                }
                for (j = 0; j < p->comp->pmc_numlevels; j++) {
                        if ((p->comp->pmc_lvals[j] < 0) || ((j > 0) &&
                            (p->comp->pmc_lvals[j] <=
                            p->comp->pmc_lvals[j - 1]))) {
                                PMD(PMD_ERROR, ("%s: comp %s of %s@%s(%s#%d) "
                                    "not mono. incr, %d follows %d\n", pmf,
                                    p->comp->pmc_name, PM_DEVICE(dip),
                                    p->comp->pmc_lvals[j],
                                    p->comp->pmc_lvals[j - 1]))
                                goto errout;
                        }
                }
                ret[i] = *p->comp;      /* struct assignment */
                for (j = 0; j < i; j++) {
                        /*
                         * Test for unique component names
                         */
                        if (strcmp(ret[j].pmc_name, ret[i].pmc_name) == 0) {
                                PMD(PMD_ERROR, ("%s: %s of %s@%s(%s#%d) not "
                                    "unique\n", pmf, ret[j].pmc_name,
                                    PM_DEVICE(dip)))
                                goto errout;
                        }
                }
                ptail = p;
                p = p->next;
                phead = p;      /* errout depends on phead making sense */
                kmem_free(ptail->comp, sizeof (*ptail->comp));
                kmem_free(ptail, sizeof (*ptail));
        }
out:
        ddi_prop_free(pp);
        if (lvals)
                kmem_free(lvals, nelems * sizeof (int));
        if (lszs)
                kmem_free(lszs, nelems * sizeof (int));
        if (lnames)
                kmem_free(lnames, nelems * sizeof (char *));
        if (np)
                kmem_free(np, nelems * sizeof (int));
        return (ret);

errout:
        e_pm_destroy_components(dip);
        *errp = 1;      /* signal failure */
        cmn_err(CE_CONT, "!pm: %s property ", pmcompstr);
        for (i = 0; i < nelems - 1; i++)
                cmn_err(CE_CONT, "!'%s', ", pp[i]);
        if (nelems != 0)
                cmn_err(CE_CONT, "!'%s'", pp[nelems - 1]);
        cmn_err(CE_CONT, "! for %s@%s(%s#%d) is ill-formed.\n", PM_DEVICE(dip));
        for (p = phead; p; ) {
                pm_comp_t *pp;
                int n;

                ptail = p;
                /*
                 * Free component data structures
                 */
                pp = p->comp;
                n = pp->pmc_numlevels;
                if (pp->pmc_name_sz) {
                        kmem_free(pp->pmc_name, pp->pmc_name_sz);
                }
                if (pp->pmc_lnames_sz) {
                        kmem_free(pp->pmc_lname_buf, pp->pmc_lnames_sz);
                }
                if (pp->pmc_lnames) {
                        kmem_free(pp->pmc_lnames, n * (sizeof (char *)));
                }
                if (pp->pmc_thresh) {
                        kmem_free(pp->pmc_thresh, n * (sizeof (int)));
                }
                if (pp->pmc_lvals) {
                        kmem_free(pp->pmc_lvals, n * (sizeof (int)));
                }
                p = ptail->next;
                kmem_free(ptail, sizeof (*ptail));
        }
        if (ret != NULL)
                kmem_free(ret, components * sizeof (pm_comp_t));
        ret = NULL;
        goto out;
}

/*
 * Set threshold values for a devices components by dividing the target
 * threshold (base) by the number of transitions and assign each transition
 * that threshold.  This will get the entire device down in the target time if
 * all components are idle and even if there are dependencies among components.
 *
 * Devices may well get powered all the way down before the target time, but
 * at least the EPA will be happy.
 */
void
pm_set_device_threshold(dev_info_t *dip, int base, int flag)
{
        PMD_FUNC(pmf, "set_device_threshold")
        int target_threshold = (base * 95) / 100;
        int level, comp;                /* loop counters */
        int transitions = 0;
        int ncomp = PM_NUMCMPTS(dip);
        int thresh;
        int remainder;
        pm_comp_t *pmc;
        int i, circ;

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        PM_LOCK_DIP(dip);
        /*
         * First we handle the easy one.  If we're setting the default
         * threshold for a node with children, then we set it to the
         * default nexus threshold (currently 0) and mark it as default
         * nexus threshold instead
         */
        if (PM_IS_NEXUS(dip)) {
                if (flag == PMC_DEF_THRESH) {
                        PMD(PMD_THRESH, ("%s: [%s@%s(%s#%d) NEXDEF]\n", pmf,
                            PM_DEVICE(dip)))
                        thresh = pm_default_nexus_threshold;
                        for (comp = 0; comp < ncomp; comp++) {
                                pmc = &PM_CP(dip, comp)->pmc_comp;
                                for (level = 1; level < pmc->pmc_numlevels;
                                    level++) {
                                        pmc->pmc_thresh[level] = thresh;
                                }
                        }
                        DEVI(dip)->devi_pm_dev_thresh =
                            pm_default_nexus_threshold;
                        /*
                         * If the nexus node is being reconfigured back to
                         * the default threshold, adjust the notlowest count.
                         */
                        if (DEVI(dip)->devi_pm_flags &
                            (PMC_DEV_THRESH|PMC_COMP_THRESH)) {
                                PM_LOCK_POWER(dip, &circ);
                                for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                                        if (PM_CURPOWER(dip, i) == 0)
                                                continue;
                                        mutex_enter(&pm_compcnt_lock);
                                        ASSERT(pm_comps_notlowest);
                                        pm_comps_notlowest--;
                                        PMD(PMD_LEVEL, ("%s: %s@%s(%s#%d) decr "
                                            "notlowest to %d\n", pmf,
                                            PM_DEVICE(dip), pm_comps_notlowest))
                                        if (pm_comps_notlowest == 0)
                                                pm_ppm_notify_all_lowest(dip,
                                                    PM_ALL_LOWEST);
                                        mutex_exit(&pm_compcnt_lock);
                                }
                                PM_UNLOCK_POWER(dip, circ);
                        }
                        DEVI(dip)->devi_pm_flags &= PMC_THRESH_NONE;
                        DEVI(dip)->devi_pm_flags |= PMC_NEXDEF_THRESH;
                        PM_UNLOCK_DIP(dip);
                        return;
                } else if (DEVI(dip)->devi_pm_flags & PMC_NEXDEF_THRESH) {
                        /*
                         * If the nexus node is being configured for a
                         * non-default threshold, include that node in
                         * the notlowest accounting.
                         */
                        PM_LOCK_POWER(dip, &circ);
                        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                                if (PM_CURPOWER(dip, i) == 0)
                                        continue;
                                mutex_enter(&pm_compcnt_lock);
                                if (pm_comps_notlowest == 0)
                                        pm_ppm_notify_all_lowest(dip,
                                            PM_NOT_ALL_LOWEST);
                                pm_comps_notlowest++;
                                PMD(PMD_LEVEL, ("%s: %s@%s(%s#%d) incr "
                                    "notlowest to %d\n", pmf,
                                    PM_DEVICE(dip), pm_comps_notlowest))
                                mutex_exit(&pm_compcnt_lock);
                        }
                        PM_UNLOCK_POWER(dip, circ);
                }
        }
        /*
         * Compute the total number of transitions for all components
         * of the device.  Distribute the threshold evenly over them
         */
        for (comp = 0; comp < ncomp; comp++) {
                pmc = &PM_CP(dip, comp)->pmc_comp;
                ASSERT(pmc->pmc_numlevels > 1);
                transitions += pmc->pmc_numlevels - 1;
        }
        ASSERT(transitions);
        thresh = target_threshold / transitions;

        for (comp = 0; comp < ncomp; comp++) {
                pmc = &PM_CP(dip, comp)->pmc_comp;
                for (level = 1; level < pmc->pmc_numlevels; level++) {
                        pmc->pmc_thresh[level] = thresh;
                }
        }

#ifdef DEBUG
        for (comp = 0; comp < ncomp; comp++) {
                pmc = &PM_CP(dip, comp)->pmc_comp;
                for (level = 1; level < pmc->pmc_numlevels; level++) {
                        PMD(PMD_THRESH, ("%s: thresh before %s@%s(%s#%d) "
                            "comp=%d, level=%d, %d\n", pmf, PM_DEVICE(dip),
                            comp, level, pmc->pmc_thresh[level]))
                }
        }
#endif
        /*
         * Distribute any remainder till they are all gone
         */
        remainder = target_threshold - thresh * transitions;
        level = 1;
#ifdef DEBUG
        PMD(PMD_THRESH, ("%s: remainder=%d target_threshold=%d thresh=%d "
            "trans=%d\n", pmf, remainder, target_threshold, thresh,
            transitions))
#endif
        while (remainder > 0) {
                comp = 0;
                while (remainder && (comp < ncomp)) {
                        pmc = &PM_CP(dip, comp)->pmc_comp;
                        if (level < pmc->pmc_numlevels) {
                                pmc->pmc_thresh[level] += 1;
                                remainder--;
                        }
                        comp++;
                }
                level++;
        }
#ifdef DEBUG
        for (comp = 0; comp < ncomp; comp++) {
                pmc = &PM_CP(dip, comp)->pmc_comp;
                for (level = 1; level < pmc->pmc_numlevels; level++) {
                        PMD(PMD_THRESH, ("%s: thresh after %s@%s(%s#%d) "
                            "comp=%d level=%d, %d\n", pmf, PM_DEVICE(dip),
                            comp, level, pmc->pmc_thresh[level]))
                }
        }
#endif
        ASSERT(PM_IAM_LOCKING_DIP(dip));
        DEVI(dip)->devi_pm_dev_thresh = base;
        DEVI(dip)->devi_pm_flags &= PMC_THRESH_NONE;
        DEVI(dip)->devi_pm_flags |= flag;
        PM_UNLOCK_DIP(dip);
}

/*
 * Called when there is no old-style platform power management driver
 */
static int
ddi_no_platform_power(power_req_t *req)
{
        _NOTE(ARGUNUSED(req))
        return (DDI_FAILURE);
}

/*
 * This function calls the entry point supplied by the platform-specific
 * pm driver to bring the device component 'pm_cmpt' to power level 'pm_level'.
 * The use of global for getting the  function name from platform-specific
 * pm driver is not ideal, but it is simple and efficient.
 * The previous property lookup was being done in the idle loop on swift
 * systems without pmc chips and hurt deskbench performance as well as
 * violating scheduler locking rules
 */
int     (*pm_platform_power)(power_req_t *) = ddi_no_platform_power;

/*
 * Old obsolete interface for a device to request a power change (but only
 * an increase in power)
 */
int
ddi_dev_is_needed(dev_info_t *dip, int cmpt, int level)
{
        return (pm_raise_power(dip, cmpt, level));
}

/*
 * The old obsolete interface to platform power management.  Only used by
 * Gypsy platform and APM on X86.
 */
int
ddi_power(dev_info_t *dip, int pm_cmpt, int pm_level)
{
        power_req_t     request;

        request.request_type = PMR_SET_POWER;
        request.req.set_power_req.who = dip;
        request.req.set_power_req.cmpt = pm_cmpt;
        request.req.set_power_req.level = pm_level;
        return (ddi_ctlops(dip, dip, DDI_CTLOPS_POWER, &request, NULL));
}

/*
 * A driver can invoke this from its detach routine when DDI_SUSPEND is
 * passed.  Returns true if subsequent processing could result in power being
 * removed from the device.  The arg is not currently used because it is
 * implicit in the operation of cpr/DR.
 */
int
ddi_removing_power(dev_info_t *dip)
{
        _NOTE(ARGUNUSED(dip))
        return (pm_powering_down);
}

/*
 * Returns true if a device indicates that its parent handles suspend/resume
 * processing for it.
 */
int
e_ddi_parental_suspend_resume(dev_info_t *dip)
{
        return (DEVI(dip)->devi_pm_flags & PMC_PARENTAL_SR);
}

/*
 * Called for devices which indicate that their parent does suspend/resume
 * handling for them
 */
int
e_ddi_suspend(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        power_req_t     request;
        request.request_type = PMR_SUSPEND;
        request.req.suspend_req.who = dip;
        request.req.suspend_req.cmd = cmd;
        return (ddi_ctlops(dip, dip, DDI_CTLOPS_POWER, &request, NULL));
}

/*
 * Called for devices which indicate that their parent does suspend/resume
 * handling for them
 */
int
e_ddi_resume(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        power_req_t     request;
        request.request_type = PMR_RESUME;
        request.req.resume_req.who = dip;
        request.req.resume_req.cmd = cmd;
        return (ddi_ctlops(dip, dip, DDI_CTLOPS_POWER, &request, NULL));
}

/*
 * Old obsolete exported interface for drivers to create components.
 * This is now handled by exporting the pm-components property.
 */
int
pm_create_components(dev_info_t *dip, int num_components)
{
        PMD_FUNC(pmf, "pm_create_components")

        if (num_components < 1)
                return (DDI_FAILURE);

        if (!DEVI_IS_ATTACHING(dip)) {
                return (DDI_FAILURE);
        }

        /* don't need to lock dip because attach is single threaded */
        if (DEVI(dip)->devi_pm_components) {
                PMD(PMD_ERROR, ("%s: %s@%s(%s#%d) already has %d\n", pmf,
                    PM_DEVICE(dip), PM_NUMCMPTS(dip)))
                return (DDI_FAILURE);
        }
        e_pm_create_components(dip, num_components);
        DEVI(dip)->devi_pm_flags |= PMC_BC;
        e_pm_default_components(dip, num_components);
        return (DDI_SUCCESS);
}

/*
 * Obsolete interface previously called by drivers to destroy their components
 * at detach time.  This is now done automatically.  However, we need to keep
 * this for the old drivers.
 */
void
pm_destroy_components(dev_info_t *dip)
{
        PMD_FUNC(pmf, "pm_destroy_components")
        dev_info_t *pdip = ddi_get_parent(dip);

        PMD(PMD_REMDEV | PMD_KIDSUP, ("%s: %s@%s(%s#%d)\n", pmf,
            PM_DEVICE(dip)))
        ASSERT(DEVI_IS_DETACHING(dip));
#ifdef DEBUG
        if (!PM_ISBC(dip))
                cmn_err(CE_WARN, "!driver exporting pm-components property "
                    "(%s@%s) calls pm_destroy_components", PM_NAME(dip),
                    PM_ADDR(dip));
#endif
        /*
         * We ignore this unless this is an old-style driver, except for
         * printing the message above
         */
        if (PM_NUMCMPTS(dip) == 0 || !PM_ISBC(dip)) {
                PMD(PMD_REMDEV, ("%s: ignore %s@%s(%s#%d)\n", pmf,
                    PM_DEVICE(dip)))
                return;
        }
        ASSERT(PM_GET_PM_INFO(dip));

        /*
         * pm_unmanage will clear info pointer later, after dealing with
         * dependencies
         */
        ASSERT(!PM_GET_PM_SCAN(dip));   /* better be gone already */
        /*
         * Now adjust parent's kidsupcnt.  We check only comp 0.
         * Parents that get notification are not adjusted because their
         * kidsupcnt is always 0 (or 1 during probe and attach).
         */
        if ((PM_CURPOWER(dip, 0) != 0) && pdip && !PM_WANTS_NOTIFICATION(pdip))
                pm_rele_power(pdip);
#ifdef DEBUG
        else {
                PMD(PMD_KIDSUP, ("%s: kuc stays %s@%s(%s#%d) comps gone\n",
                    pmf, PM_DEVICE(dip)))
        }
#endif
        e_pm_destroy_components(dip);
        /*
         * Forget we ever knew anything about the components of this  device
         */
        DEVI(dip)->devi_pm_flags &=
            ~(PMC_BC | PMC_COMPONENTS_DONE | PMC_COMPONENTS_FAILED);
}

/*
 * Exported interface for a driver to set a component busy.
 */
int
pm_busy_component(dev_info_t *dip, int cmpt)
{
        struct pm_component *cp;

        ASSERT(dip != NULL);
        if (!e_pm_valid_info(dip, NULL) || !e_pm_valid_comp(dip, cmpt, &cp))
                return (DDI_FAILURE);
        PM_LOCK_BUSY(dip);
        cp->pmc_busycount++;
        cp->pmc_timestamp = 0;
        PM_UNLOCK_BUSY(dip);
        return (DDI_SUCCESS);
}

/*
 * Exported interface for a driver to set a component idle.
 */
int
pm_idle_component(dev_info_t *dip, int cmpt)
{
        PMD_FUNC(pmf, "pm_idle_component")
        struct pm_component *cp;
        pm_scan_t       *scanp = PM_GET_PM_SCAN(dip);

        if (!e_pm_valid_info(dip, NULL) || !e_pm_valid_comp(dip, cmpt, &cp))
                return (DDI_FAILURE);

        PM_LOCK_BUSY(dip);
        if (cp->pmc_busycount) {
                if (--(cp->pmc_busycount) == 0)
                        cp->pmc_timestamp = gethrestime_sec();
        } else {
                cp->pmc_timestamp = gethrestime_sec();
        }

        PM_UNLOCK_BUSY(dip);

        /*
         * if device becomes idle during idle down period, try scan it down
         */
        if (scanp && PM_IS_PID(dip)) {
                PMD(PMD_IDLEDOWN, ("%s: %s@%s(%s#%d) idle.\n", pmf,
                    PM_DEVICE(dip)))
                pm_rescan(dip);
                return (DDI_SUCCESS);
        }

        /*
         * handle scan not running with nexus threshold == 0
         */

        if (PM_IS_NEXUS(dip) && (cp->pmc_busycount == 0)) {
                pm_rescan(dip);
        }

        return (DDI_SUCCESS);
}

/*
 * This is the old  obsolete interface called by drivers to set their normal
 * power.  Thus we can't fix its behavior or return a value.
 * This functionality is replaced by the pm-component property.
 * We'll only get components destroyed while no power management is
 * going on (and the device is detached), so we don't need a mutex here
 */
void
pm_set_normal_power(dev_info_t *dip, int comp, int level)
{
        PMD_FUNC(pmf, "set_normal_power")
#ifdef DEBUG
        if (!PM_ISBC(dip))
                cmn_err(CE_WARN, "!call to pm_set_normal_power() by %s@%s "
                    "(driver exporting pm-components property) ignored",
                    PM_NAME(dip), PM_ADDR(dip));
#endif
        if (PM_ISBC(dip)) {
                PMD(PMD_NORM, ("%s: %s@%s(%s#%d) set normal power comp=%d, "
                    "level=%d\n", pmf, PM_DEVICE(dip), comp, level))
                e_pm_set_max_power(dip, comp, level);
                e_pm_default_levels(dip, PM_CP(dip, comp), level);
        }
}

/*
 * Called on a successfully detached driver to free pm resources
 */
static void
pm_stop(dev_info_t *dip)
{
        PMD_FUNC(pmf, "stop")
        dev_info_t *pdip = ddi_get_parent(dip);

        ASSERT(!PM_IAM_LOCKING_DIP(dip));
        /* stopping scan, destroy scan data structure */
        if (!PM_ISBC(dip)) {
                pm_scan_stop(dip);
                pm_scan_fini(dip);
        }

        if (PM_GET_PM_INFO(dip) != NULL) {
                if (pm_unmanage(dip) == DDI_SUCCESS) {
                        /*
                         * Old style driver may have called
                         * pm_destroy_components already, but just in case ...
                         */
                        e_pm_destroy_components(dip);
                } else {
                        PMD(PMD_FAIL, ("%s: can't pm_unmanage %s@%s(%s#%d)\n",
                            pmf, PM_DEVICE(dip)))
                }
        } else {
                if (PM_NUMCMPTS(dip))
                        e_pm_destroy_components(dip);
                else {
                        if (DEVI(dip)->devi_pm_flags & PMC_NOPMKID) {
                                DEVI(dip)->devi_pm_flags &= ~PMC_NOPMKID;
                                if (pdip && !PM_WANTS_NOTIFICATION(pdip)) {
                                        pm_rele_power(pdip);
                                } else if (pdip &&
                                    MDI_VHCI(pdip) && MDI_CLIENT(dip)) {
                                        (void) mdi_power(pdip,
                                            MDI_PM_RELE_POWER,
                                            (void *)dip, NULL, 0);
                                }
                        }
                }
        }
}

/*
 * The node is the subject of a reparse pm props ioctl. Throw away the old
 * info and start over.
 */
int
e_new_pm_props(dev_info_t *dip)
{
        if (PM_GET_PM_INFO(dip) != NULL) {
                pm_stop(dip);

                if (e_pm_manage(dip, PM_STYLE_NEW) != DDI_SUCCESS) {
                        return (DDI_FAILURE);
                }
        }
        e_pm_props(dip);
        return (DDI_SUCCESS);
}

/*
 * Device has been attached, so process its pm properties
 */
void
e_pm_props(dev_info_t *dip)
{
        char *pp;
        int len;
        int flags = 0;
        int propflag = DDI_PROP_DONTPASS|DDI_PROP_CANSLEEP;

        /*
         * It doesn't matter if we do this more than once, we should always
         * get the same answers, and if not, then the last one in is the
         * best one.
         */
        if (ddi_getlongprop(DDI_DEV_T_ANY, dip, propflag, "pm-hardware-state",
            (caddr_t)&pp, &len) == DDI_PROP_SUCCESS) {
                if (strcmp(pp, "needs-suspend-resume") == 0) {
                        flags = PMC_NEEDS_SR;
                } else if (strcmp(pp, "no-suspend-resume") == 0) {
                        flags = PMC_NO_SR;
                } else if (strcmp(pp, "parental-suspend-resume") == 0) {
                        flags = PMC_PARENTAL_SR;
                } else {
                        cmn_err(CE_NOTE, "!device %s@%s has unrecognized "
                            "%s property value '%s'", PM_NAME(dip),
                            PM_ADDR(dip), "pm-hardware-state", pp);
                }
                kmem_free(pp, len);
        }
        /*
         * This next segment (PMC_WANTS_NOTIFY) is in
         * support of nexus drivers which will want to be involved in
         * (or at least notified of) their child node's power level transitions.
         * "pm-want-child-notification?" is defined by the parent.
         */
        if (ddi_prop_exists(DDI_DEV_T_ANY, dip, propflag,
            "pm-want-child-notification?") && PM_HAS_BUS_POWER(dip))
                flags |= PMC_WANTS_NOTIFY;
        ASSERT(PM_HAS_BUS_POWER(dip) || !ddi_prop_exists(DDI_DEV_T_ANY,
            dip, propflag, "pm-want-child-notification?"));
        if (ddi_prop_exists(DDI_DEV_T_ANY, dip, propflag,
            "no-involuntary-power-cycles"))
                flags |= PMC_NO_INVOL;
        /*
         * Is the device a CPU device?
         */
        if (ddi_getlongprop(DDI_DEV_T_ANY, dip, propflag, "pm-class",
            (caddr_t)&pp, &len) == DDI_PROP_SUCCESS) {
                if (strcmp(pp, "CPU") == 0) {
                        flags |= PMC_CPU_DEVICE;
                } else {
                        cmn_err(CE_NOTE, "!device %s@%s has unrecognized "
                            "%s property value '%s'", PM_NAME(dip),
                            PM_ADDR(dip), "pm-class", pp);
                }
                kmem_free(pp, len);
        }
        /* devfs single threads us */
        DEVI(dip)->devi_pm_flags |= flags;
}

/*
 * This is the DDI_CTLOPS_POWER handler that is used when there is no ppm
 * driver which has claimed a node.
 * Sets old_power in arg struct.
 */
static int
pm_default_ctlops(dev_info_t *dip, dev_info_t *rdip,
    ddi_ctl_enum_t ctlop, void *arg, void *result)
{
        _NOTE(ARGUNUSED(dip))
        PMD_FUNC(pmf, "ctlops")
        power_req_t *reqp = (power_req_t *)arg;
        int retval;
        dev_info_t *target_dip;
        int new_level, old_level, cmpt;
#ifdef PMDDEBUG
        char *format;
#endif

        /*
         * The interface for doing the actual power level changes is now
         * through the DDI_CTLOPS_POWER bus_ctl, so that we can plug in
         * different platform-specific power control drivers.
         *
         * This driver implements the "default" version of this interface.
         * If no ppm driver has been installed then this interface is called
         * instead.
         */
        ASSERT(dip == NULL);
        switch (ctlop) {
        case DDI_CTLOPS_POWER:
                switch (reqp->request_type) {
                case PMR_PPM_SET_POWER:
                {
                        target_dip = reqp->req.ppm_set_power_req.who;
                        ASSERT(target_dip == rdip);
                        new_level = reqp->req.ppm_set_power_req.new_level;
                        cmpt = reqp->req.ppm_set_power_req.cmpt;
                        /* pass back old power for the PM_LEVEL_UNKNOWN case */
                        old_level = PM_CURPOWER(target_dip, cmpt);
                        reqp->req.ppm_set_power_req.old_level = old_level;
                        retval = pm_power(target_dip, cmpt, new_level);
                        PMD(PMD_PPM, ("%s: PPM_SET_POWER %s@%s(%s#%d)[%d] %d->"
                            "%d %s\n", pmf, PM_DEVICE(target_dip), cmpt,
                            old_level, new_level, (retval == DDI_SUCCESS ?
                            "chd" : "no chg")))
                        return (retval);
                }

                case PMR_PPM_PRE_DETACH:
                case PMR_PPM_POST_DETACH:
                case PMR_PPM_PRE_ATTACH:
                case PMR_PPM_POST_ATTACH:
                case PMR_PPM_PRE_PROBE:
                case PMR_PPM_POST_PROBE:
                case PMR_PPM_PRE_RESUME:
                case PMR_PPM_INIT_CHILD:
                case PMR_PPM_UNINIT_CHILD:
#ifdef PMDDEBUG
                        switch (reqp->request_type) {
                                case PMR_PPM_PRE_DETACH:
                                        format = "%s: PMR_PPM_PRE_DETACH "
                                            "%s@%s(%s#%d)\n";
                                        break;
                                case PMR_PPM_POST_DETACH:
                                        format = "%s: PMR_PPM_POST_DETACH "
                                            "%s@%s(%s#%d) rets %d\n";
                                        break;
                                case PMR_PPM_PRE_ATTACH:
                                        format = "%s: PMR_PPM_PRE_ATTACH "
                                            "%s@%s(%s#%d)\n";
                                        break;
                                case PMR_PPM_POST_ATTACH:
                                        format = "%s: PMR_PPM_POST_ATTACH "
                                            "%s@%s(%s#%d) rets %d\n";
                                        break;
                                case PMR_PPM_PRE_PROBE:
                                        format = "%s: PMR_PPM_PRE_PROBE "
                                            "%s@%s(%s#%d)\n";
                                        break;
                                case PMR_PPM_POST_PROBE:
                                        format = "%s: PMR_PPM_POST_PROBE "
                                            "%s@%s(%s#%d) rets %d\n";
                                        break;
                                case PMR_PPM_PRE_RESUME:
                                        format = "%s: PMR_PPM_PRE_RESUME "
                                            "%s@%s(%s#%d) rets %d\n";
                                        break;
                                case PMR_PPM_INIT_CHILD:
                                        format = "%s: PMR_PPM_INIT_CHILD "
                                            "%s@%s(%s#%d)\n";
                                        break;
                                case PMR_PPM_UNINIT_CHILD:
                                        format = "%s: PMR_PPM_UNINIT_CHILD "
                                            "%s@%s(%s#%d)\n";
                                        break;
                                default:
                                        break;
                        }
                        PMD(PMD_PPM, (format, pmf, PM_DEVICE(rdip),
                            reqp->req.ppm_config_req.result))
#endif
                        return (DDI_SUCCESS);

                case PMR_PPM_POWER_CHANGE_NOTIFY:
                        /*
                         * Nothing for us to do
                         */
                        ASSERT(reqp->req.ppm_notify_level_req.who == rdip);
                        PMD(PMD_PPM, ("%s: PMR_PPM_POWER_CHANGE_NOTIFY "
                            "%s@%s(%s#%d)[%d] %d->%d\n", pmf,
                            PM_DEVICE(reqp->req.ppm_notify_level_req.who),
                            reqp->req.ppm_notify_level_req.cmpt,
                            PM_CURPOWER(reqp->req.ppm_notify_level_req.who,
                            reqp->req.ppm_notify_level_req.cmpt),
                            reqp->req.ppm_notify_level_req.new_level))
                        return (DDI_SUCCESS);

                case PMR_PPM_UNMANAGE:
                        PMD(PMD_PPM, ("%s: PMR_PPM_UNMANAGE %s@%s(%s#%d)\n",
                            pmf, PM_DEVICE(rdip)))
                        return (DDI_SUCCESS);

                case PMR_PPM_LOCK_POWER:
                        pm_lock_power_single(reqp->req.ppm_lock_power_req.who,
                            reqp->req.ppm_lock_power_req.circp);
                        return (DDI_SUCCESS);

                case PMR_PPM_UNLOCK_POWER:
                        pm_unlock_power_single(
                            reqp->req.ppm_unlock_power_req.who,
                            reqp->req.ppm_unlock_power_req.circ);
                        return (DDI_SUCCESS);

                case PMR_PPM_TRY_LOCK_POWER:
                        *(int *)result = pm_try_locking_power_single(
                            reqp->req.ppm_lock_power_req.who,
                            reqp->req.ppm_lock_power_req.circp);
                        return (DDI_SUCCESS);

                case PMR_PPM_POWER_LOCK_OWNER:
                        target_dip = reqp->req.ppm_power_lock_owner_req.who;
                        ASSERT(target_dip == rdip);
                        reqp->req.ppm_power_lock_owner_req.owner =
                            DEVI(rdip)->devi_busy_thread;
                        return (DDI_SUCCESS);
                default:
                        PMD(PMD_ERROR, ("%s: default!\n", pmf))
                        return (DDI_FAILURE);
                }

        default:
                PMD(PMD_ERROR, ("%s: unknown\n", pmf))
                return (DDI_FAILURE);
        }
}

/*
 * We overload the bus_ctl ops here--perhaps we ought to have a distinct
 * power_ops struct for this functionality instead?
 * However, we only ever do this on a ppm driver.
 */
int
pm_ctlops(dev_info_t *d, dev_info_t *r, ddi_ctl_enum_t op, void *a, void *v)
{
        int (*fp)();

        /* if no ppm handler, call the default routine */
        if (d == NULL) {
                return (pm_default_ctlops(d, r, op, a, v));
        }
        if (!d || !r)
                return (DDI_FAILURE);
        ASSERT(DEVI(d)->devi_ops && DEVI(d)->devi_ops->devo_bus_ops &&
            DEVI(d)->devi_ops->devo_bus_ops->bus_ctl);

        fp = DEVI(d)->devi_ops->devo_bus_ops->bus_ctl;
        return ((*fp)(d, r, op, a, v));
}

/*
 * Called on a node when attach completes or the driver makes its first pm
 * call (whichever comes first).
 * In the attach case, device may not be power manageable at all.
 * Don't need to lock the dip because we're single threaded by the devfs code
 */
static int
pm_start(dev_info_t *dip)
{
        PMD_FUNC(pmf, "start")
        int ret;
        dev_info_t *pdip = ddi_get_parent(dip);
        int e_pm_manage(dev_info_t *, int);
        void pm_noinvol_specd(dev_info_t *dip);

        e_pm_props(dip);
        pm_noinvol_specd(dip);
        /*
         * If this dip has already been processed, don't mess with it
         * (but decrement the speculative count we did above, as whatever
         * code put it under pm already will have dealt with it)
         */
        if (PM_GET_PM_INFO(dip)) {
                PMD(PMD_KIDSUP, ("%s: pm already done for %s@%s(%s#%d)\n",
                    pmf, PM_DEVICE(dip)))
                return (0);
        }
        ret = e_pm_manage(dip, PM_STYLE_UNKNOWN);

        if (PM_GET_PM_INFO(dip) == NULL) {
                /*
                 * keep the kidsupcount increment as is
                 */
                DEVI(dip)->devi_pm_flags |= PMC_NOPMKID;
                if (pdip && !PM_WANTS_NOTIFICATION(pdip)) {
                        pm_hold_power(pdip);
                } else if (pdip && MDI_VHCI(pdip) && MDI_CLIENT(dip)) {
                        (void) mdi_power(pdip, MDI_PM_HOLD_POWER,
                            (void *)dip, NULL, 0);
                }

                PMD(PMD_KIDSUP, ("%s: pm of %s@%s(%s#%d) failed, parent "
                    "left up\n", pmf, PM_DEVICE(dip)))
        }

        return (ret);
}

/*
 * Keep a list of recorded thresholds.  For now we just keep a list and
 * search it linearly.  We don't expect too many entries.  Can always hash it
 * later if we need to.
 */
void
pm_record_thresh(pm_thresh_rec_t *rp)
{
        pm_thresh_rec_t *pptr, *ptr;

        ASSERT(*rp->ptr_physpath);
        rw_enter(&pm_thresh_rwlock, RW_WRITER);
        for (pptr = NULL, ptr = pm_thresh_head;
            ptr; pptr = ptr,  ptr = ptr->ptr_next) {
                if (strcmp(rp->ptr_physpath, ptr->ptr_physpath) == 0) {
                        /* replace this one */
                        rp->ptr_next = ptr->ptr_next;
                        if (pptr) {
                                pptr->ptr_next = rp;
                        } else {
                                pm_thresh_head = rp;
                        }
                        rw_exit(&pm_thresh_rwlock);
                        kmem_free(ptr, ptr->ptr_size);
                        return;
                }
                continue;
        }
        /*
         * There was not a match in the list, insert this one in front
         */
        if (pm_thresh_head) {
                rp->ptr_next = pm_thresh_head;
                pm_thresh_head = rp;
        } else {
                rp->ptr_next = NULL;
                pm_thresh_head = rp;
        }
        rw_exit(&pm_thresh_rwlock);
}

/*
 * Create a new dependency record and hang a new dependency entry off of it
 */
pm_pdr_t *
newpdr(char *kept, char *keeps, int isprop)
{
        size_t size = strlen(kept) + strlen(keeps) + 2 + sizeof (pm_pdr_t);
        pm_pdr_t *p = kmem_zalloc(size, KM_SLEEP);
        p->pdr_size = size;
        p->pdr_isprop = isprop;
        p->pdr_kept_paths = NULL;
        p->pdr_kept_count = 0;
        p->pdr_kept = (char *)((intptr_t)p + sizeof (pm_pdr_t));
        (void) strcpy(p->pdr_kept, kept);
        p->pdr_keeper = (char *)((intptr_t)p->pdr_kept + strlen(kept) + 1);
        (void) strcpy(p->pdr_keeper, keeps);
        ASSERT((intptr_t)p->pdr_keeper + strlen(p->pdr_keeper) + 1 <=
            (intptr_t)p + size);
        ASSERT((intptr_t)p->pdr_kept + strlen(p->pdr_kept) + 1 <=
            (intptr_t)p + size);
        return (p);
}

/*
 * Keep a list of recorded dependencies.  We only keep the
 * keeper -> kept list for simplification. At this point We do not
 * care about whether the devices are attached or not yet,
 * this would be done in pm_keeper() and pm_kept().
 * If a PM_RESET_PM happens, then we tear down and forget the dependencies,
 * and it is up to the user to issue the ioctl again if they want it
 * (e.g. pmconfig)
 * Returns true if dependency already exists in the list.
 */
int
pm_record_keeper(char *kept, char *keeper, int isprop)
{
        PMD_FUNC(pmf, "record_keeper")
        pm_pdr_t *npdr, *ppdr, *pdr;

        PMD(PMD_KEEPS, ("%s: %s, %s\n", pmf, kept, keeper))
        ASSERT(kept && keeper);
#ifdef DEBUG
        if (pm_debug & PMD_KEEPS)
                prdeps("pm_record_keeper entry");
#endif
        for (ppdr = NULL, pdr = pm_dep_head; pdr;
            ppdr = pdr, pdr = pdr->pdr_next) {
                PMD(PMD_KEEPS, ("%s: check %s, %s\n", pmf, pdr->pdr_kept,
                    pdr->pdr_keeper))
                if (strcmp(kept, pdr->pdr_kept) == 0 &&
                    strcmp(keeper, pdr->pdr_keeper) == 0) {
                        PMD(PMD_KEEPS, ("%s: match\n", pmf))
                        return (1);
                }
        }
        /*
         * We did not find any match, so we have to make an entry
         */
        npdr = newpdr(kept, keeper, isprop);
        if (ppdr) {
                ASSERT(ppdr->pdr_next == NULL);
                ppdr->pdr_next = npdr;
        } else {
                ASSERT(pm_dep_head == NULL);
                pm_dep_head = npdr;
        }
#ifdef DEBUG
        if (pm_debug & PMD_KEEPS)
                prdeps("pm_record_keeper after new record");
#endif
        if (!isprop)
                pm_unresolved_deps++;
        else
                pm_prop_deps++;
        return (0);
}

/*
 * Look up this device in the set of devices we've seen ioctls for
 * to see if we are holding a threshold spec for it.  If so, make it so.
 * At ioctl time, we were given the physical path of the device.
 */
int
pm_thresh_specd(dev_info_t *dip)
{
        void pm_apply_recorded_thresh(dev_info_t *, pm_thresh_rec_t *);
        char *path = 0;
        char pathbuf[MAXNAMELEN];
        pm_thresh_rec_t *rp;

        path = ddi_pathname(dip, pathbuf);

        rw_enter(&pm_thresh_rwlock, RW_READER);
        for (rp = pm_thresh_head; rp; rp = rp->ptr_next) {
                if (strcmp(rp->ptr_physpath, path) != 0)
                        continue;
                pm_apply_recorded_thresh(dip, rp);
                rw_exit(&pm_thresh_rwlock);
                return (1);
        }
        rw_exit(&pm_thresh_rwlock);
        return (0);
}

static int
pm_set_keeping(dev_info_t *keeper, dev_info_t *kept)
{
        PMD_FUNC(pmf, "set_keeping")
        int j, up = 0, circ;
        void prdeps(char *);

        PMD(PMD_KEEPS, ("%s: keeper=%s@%s(%s#%d), kept=%s@%s(%s#%d)\n", pmf,
            PM_DEVICE(keeper), PM_DEVICE(kept)))
#ifdef DEBUG
        if (pm_debug & PMD_KEEPS)
                prdeps("Before PAD\n");
#endif
        ASSERT(keeper != kept);
        if (PM_GET_PM_INFO(keeper) == NULL) {
                cmn_err(CE_CONT, "!device %s@%s(%s#%d) keeps up device "
                    "%s@%s(%s#%d), but the former is not power managed",
                    PM_DEVICE(keeper), PM_DEVICE(kept));
                PMD((PMD_FAIL | PMD_KEEPS), ("%s: keeper %s@%s(%s#%d) is not"
                    "power managed\n", pmf, PM_DEVICE(keeper)))
                return (0);
        }
        if (PM_GET_PM_INFO(kept) == NULL) {
                cmn_err(CE_CONT, "!device %s@%s(%s#%d) keeps up device "
                    "%s@%s(%s#%d), but the latter is not power managed",
                    PM_DEVICE(keeper), PM_DEVICE(kept));
                PMD((PMD_FAIL | PMD_KEEPS), ("%s: kept %s@%s(%s#%d) is not"
                    "power managed\n", pmf, PM_DEVICE(kept)))
                return (0);
        }

        PM_LOCK_POWER(keeper, &circ);
        for (j = 0; j < PM_NUMCMPTS(keeper); j++) {
                if (PM_CURPOWER(keeper, j)) {
                        up++;
                        break;
                }
        }
        if (up) {
                /* Bringup and maintain a hold on the kept */
                PMD(PMD_KEEPS, ("%s: place a hold on kept %s@%s(%s#%d)\n", pmf,
                    PM_DEVICE(kept)))
                bring_pmdep_up(kept, 1);
        }
        PM_UNLOCK_POWER(keeper, circ);
#ifdef DEBUG
        if (pm_debug & PMD_KEEPS)
                prdeps("After PAD\n");
#endif
        return (1);
}

/*
 * Should this device keep up another device?
 * Look up this device in the set of devices we've seen ioctls for
 * to see if we are holding a dependency spec for it.  If so, make it so.
 * Because we require the kept device to be attached already in order to
 * make the list entry (and hold it), we only need to look for keepers.
 * At ioctl time, we were given the physical path of the device.
 */
int
pm_keeper(char *keeper)
{
        PMD_FUNC(pmf, "keeper")
        int pm_apply_recorded_dep(dev_info_t *, pm_pdr_t *);
        dev_info_t *dip;
        pm_pdr_t *dp;
        dev_info_t *kept = NULL;
        int ret = 0;
        int i;

        if (!pm_unresolved_deps && !pm_prop_deps)
                return (0);
        ASSERT(keeper != NULL);
        dip = pm_name_to_dip(keeper, 1);
        if (dip == NULL)
                return (0);
        PMD(PMD_KEEPS, ("%s: keeper=%s\n", pmf, keeper))
        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (!dp->pdr_isprop) {
                        if (!pm_unresolved_deps)
                                continue;
                        PMD(PMD_KEEPS, ("%s: keeper %s\n", pmf, dp->pdr_keeper))
                        if (dp->pdr_satisfied) {
                                PMD(PMD_KEEPS, ("%s: satisfied\n", pmf))
                                continue;
                        }
                        if (strcmp(dp->pdr_keeper, keeper) == 0) {
                                ret += pm_apply_recorded_dep(dip, dp);
                        }
                } else {
                        if (strcmp(dp->pdr_keeper, keeper) != 0)
                                continue;
                        for (i = 0; i < dp->pdr_kept_count; i++) {
                                if (dp->pdr_kept_paths[i] == NULL)
                                        continue;
                                kept = pm_name_to_dip(dp->pdr_kept_paths[i], 1);
                                if (kept == NULL)
                                        continue;
                                ASSERT(ddi_prop_exists(DDI_DEV_T_ANY, kept,
                                    DDI_PROP_DONTPASS, dp->pdr_kept));
                                PMD(PMD_KEEPS, ("%s: keeper=%s@%s(%s#%d), "
                                    "kept=%s@%s(%s#%d) keptcnt=%d\n",
                                    pmf, PM_DEVICE(dip), PM_DEVICE(kept),
                                    dp->pdr_kept_count))
                                if (kept != dip) {
                                        ret += pm_set_keeping(dip, kept);
                                }
                                ddi_release_devi(kept);
                        }

                }
        }
        ddi_release_devi(dip);
        return (ret);
}

/*
 * Should this device be kept up by another device?
 * Look up all dependency recorded from PM_ADD_DEPENDENT and
 * PM_ADD_DEPENDENT_PROPERTY ioctls. Record down on the keeper's
 * kept device lists.
 */
static int
pm_kept(char *keptp)
{
        PMD_FUNC(pmf, "kept")
        pm_pdr_t *dp;
        int found = 0;
        int ret = 0;
        dev_info_t *keeper;
        dev_info_t *kept;
        size_t length;
        int i;
        char **paths;
        char *path;

        ASSERT(keptp != NULL);
        kept = pm_name_to_dip(keptp, 1);
        if (kept == NULL)
                return (0);
        PMD(PMD_KEEPS, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(kept)))
        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (dp->pdr_isprop) {
                        PMD(PMD_KEEPS, ("%s: property %s\n", pmf, dp->pdr_kept))
                        if (ddi_prop_exists(DDI_DEV_T_ANY, kept,
                            DDI_PROP_DONTPASS, dp->pdr_kept)) {
                                /*
                                 * Dont allow self dependency.
                                 */
                                if (strcmp(dp->pdr_keeper, keptp) == 0)
                                        continue;
                                keeper = pm_name_to_dip(dp->pdr_keeper, 1);
                                if (keeper == NULL)
                                        continue;
                                PMD(PMD_KEEPS, ("%s: adding to kepts path list "
                                    "%p\n", pmf, (void *)kept))
#ifdef DEBUG
                                if (pm_debug & PMD_DEP)
                                        prdeps("Before Adding from pm_kept\n");
#endif
                                /*
                                 * Add ourselves to the dip list.
                                 */
                                if (dp->pdr_kept_count == 0) {
                                        length = strlen(keptp) + 1;
                                        path =
                                            kmem_alloc(length, KM_SLEEP);
                                        paths = kmem_alloc(sizeof (char **),
                                            KM_SLEEP);
                                        (void) strcpy(path, keptp);
                                        paths[0] = path;
                                        dp->pdr_kept_paths = paths;
                                        dp->pdr_kept_count++;
                                } else {
                                        /* Check to see if already on list */
                                        for (i = 0; i < dp->pdr_kept_count;
                                            i++) {
                                                if (strcmp(keptp,
                                                    dp->pdr_kept_paths[i])
                                                    == 0) {
                                                        found++;
                                                        break;
                                                }
                                        }
                                        if (found) {
                                                ddi_release_devi(keeper);
                                                continue;
                                        }
                                        length = dp->pdr_kept_count *
                                            sizeof (char **);
                                        paths = kmem_alloc(
                                            length + sizeof (char **),
                                            KM_SLEEP);
                                        if (dp->pdr_kept_count) {
                                                bcopy(dp->pdr_kept_paths,
                                                    paths, length);
                                                kmem_free(dp->pdr_kept_paths,
                                                    length);
                                        }
                                        dp->pdr_kept_paths = paths;
                                        length = strlen(keptp) + 1;
                                        path =
                                            kmem_alloc(length, KM_SLEEP);
                                        (void) strcpy(path, keptp);
                                        dp->pdr_kept_paths[i] = path;
                                        dp->pdr_kept_count++;
                                }
#ifdef DEBUG
                                if (pm_debug & PMD_DEP)
                                        prdeps("After from pm_kept\n");
#endif
                                if (keeper) {
                                        ret += pm_set_keeping(keeper, kept);
                                        ddi_release_devi(keeper);
                                }
                        }
                } else {
                        /*
                         * pm_keeper would be called later to do
                         * the actual pm_set_keeping.
                         */
                        PMD(PMD_KEEPS, ("%s: adding to kepts path list %p\n",
                            pmf, (void *)kept))
#ifdef DEBUG
                        if (pm_debug & PMD_DEP)
                                prdeps("Before Adding from pm_kept\n");
#endif
                        if (strcmp(keptp, dp->pdr_kept) == 0) {
                                if (dp->pdr_kept_paths == NULL) {
                                        length = strlen(keptp) + 1;
                                        path =
                                            kmem_alloc(length, KM_SLEEP);
                                        paths = kmem_alloc(sizeof (char **),
                                            KM_SLEEP);
                                        (void) strcpy(path, keptp);
                                        paths[0] = path;
                                        dp->pdr_kept_paths = paths;
                                        dp->pdr_kept_count++;
                                }
                        }
#ifdef DEBUG
                        if (pm_debug & PMD_DEP)
                                prdeps("After from pm_kept\n");
#endif
                }
        }
        ddi_release_devi(kept);
        return (ret);
}

/*
 * Apply a recorded dependency.  dp specifies the dependency, and
 * keeper is already known to be the device that keeps up the other (kept) one.
 * We have to the whole tree for the "kept" device, then apply
 * the dependency (which may already be applied).
 */
int
pm_apply_recorded_dep(dev_info_t *keeper, pm_pdr_t *dp)
{
        PMD_FUNC(pmf, "apply_recorded_dep")
        dev_info_t *kept = NULL;
        int ret = 0;
        char *keptp = NULL;

        /*
         * Device to Device dependency can only be 1 to 1.
         */
        if (dp->pdr_kept_paths == NULL)
                return (0);
        keptp = dp->pdr_kept_paths[0];
        if (keptp == NULL)
                return (0);
        ASSERT(*keptp != '\0');
        kept = pm_name_to_dip(keptp, 1);
        if (kept == NULL)
                return (0);
        if (kept) {
                PMD(PMD_KEEPS, ("%s: keeper=%s, kept=%s\n", pmf,
                    dp->pdr_keeper, keptp))
                if (pm_set_keeping(keeper, kept)) {
                        ASSERT(dp->pdr_satisfied == 0);
                        dp->pdr_satisfied = 1;
                        ASSERT(pm_unresolved_deps);
                        pm_unresolved_deps--;
                        ret++;
                }
        }
        ddi_release_devi(kept);

        return (ret);
}

/*
 * Called from common/io/pm.c
 */
int
pm_cur_power(pm_component_t *cp)
{
        return (cur_power(cp));
}

/*
 * External interface to sanity-check a power level.
 */
int
pm_valid_power(dev_info_t *dip, int comp, int level)
{
        PMD_FUNC(pmf, "valid_power")

        if (comp >= 0 && comp < PM_NUMCMPTS(dip) && level >= 0)
                return (e_pm_valid_power(dip, comp, level));
        else {
                PMD(PMD_FAIL, ("%s: comp=%d, ncomp=%d, level=%d\n",
                    pmf, comp, PM_NUMCMPTS(dip), level))
                return (0);
        }
}

/*
 * Called when a device that is direct power managed needs to change state.
 * This routine arranges to block the request until the process managing
 * the device makes the change (or some other incompatible change) or
 * the process closes /dev/pm.
 */
static int
pm_block(dev_info_t *dip, int comp, int newpower, int oldpower)
{
        pm_rsvp_t *new = kmem_zalloc(sizeof (*new), KM_SLEEP);
        int ret = 0;
        void pm_dequeue_blocked(pm_rsvp_t *);
        void pm_enqueue_blocked(pm_rsvp_t *);

        ASSERT(!pm_processes_stopped);
        ASSERT(PM_IAM_LOCKING_DIP(dip));
        new->pr_dip = dip;
        new->pr_comp = comp;
        new->pr_newlevel = newpower;
        new->pr_oldlevel = oldpower;
        cv_init(&new->pr_cv, NULL, CV_DEFAULT, NULL);
        mutex_enter(&pm_rsvp_lock);
        pm_enqueue_blocked(new);
        pm_enqueue_notify(PSC_PENDING_CHANGE, dip, comp, newpower, oldpower,
            PM_CANBLOCK_BLOCK);
        PM_UNLOCK_DIP(dip);
        /*
         * truss may make the cv_wait_sig return prematurely
         */
        while (ret == 0) {
                /*
                 * Normally there will be no user context involved, but if
                 * there is (e.g. we are here via an ioctl call to a driver)
                 * then we should allow the process to abort the request,
                 * or we get an unkillable process if the same thread does
                 * PM_DIRECT_PM and pm_raise_power
                 */
                if (cv_wait_sig(&new->pr_cv, &pm_rsvp_lock) == 0) {
                        ret = PMP_FAIL;
                } else {
                        ret = new->pr_retval;
                }
        }
        pm_dequeue_blocked(new);
        mutex_exit(&pm_rsvp_lock);
        cv_destroy(&new->pr_cv);
        kmem_free(new, sizeof (*new));
        return (ret);
}

/*
 * Returns true if the process is interested in power level changes (has issued
 * PM_GET_STATE_CHANGE ioctl).
 */
int
pm_interest_registered(int clone)
{
        ASSERT(clone >= 0 && clone < PM_MAX_CLONE - 1);
        return (pm_interest[clone]);
}

static void pm_enqueue_pscc(pscc_t *, pscc_t **);

/*
 * Process with clone has just done PM_DIRECT_PM on dip, or has asked to
 * watch all state transitions (dip == NULL).  Set up data
 * structs to communicate with process about state changes.
 */
void
pm_register_watcher(int clone, dev_info_t *dip)
{
        pscc_t  *p;
        psce_t  *psce;

        /*
         * We definitely need a control struct, then we have to search to see
         * there is already an entries struct (in the dip != NULL case).
         */
        pscc_t  *pscc = kmem_zalloc(sizeof (*pscc), KM_SLEEP);
        pscc->pscc_clone = clone;
        pscc->pscc_dip = dip;

        if (dip) {
                int found = 0;
                rw_enter(&pm_pscc_direct_rwlock, RW_WRITER);
                for (p = pm_pscc_direct; p; p = p->pscc_next) {
                        /*
                         * Already an entry for this clone, so just use it
                         * for the new one (for the case where a single
                         * process is watching multiple devices)
                         */
                        if (p->pscc_clone == clone) {
                                pscc->pscc_entries = p->pscc_entries;
                                pscc->pscc_entries->psce_references++;
                                found++;
                                break;
                        }
                }
                if (!found) {           /* create a new one */
                        psce = kmem_zalloc(sizeof (psce_t), KM_SLEEP);
                        mutex_init(&psce->psce_lock, NULL, MUTEX_DEFAULT, NULL);
                        psce->psce_first =
                            kmem_zalloc(sizeof (pm_state_change_t) * PSCCOUNT,
                            KM_SLEEP);
                        psce->psce_in = psce->psce_out = psce->psce_first;
                        psce->psce_last = &psce->psce_first[PSCCOUNT - 1];
                        psce->psce_references = 1;
                        pscc->pscc_entries = psce;
                }
                pm_enqueue_pscc(pscc, &pm_pscc_direct);
                rw_exit(&pm_pscc_direct_rwlock);
        } else {
                ASSERT(!pm_interest_registered(clone));
                rw_enter(&pm_pscc_interest_rwlock, RW_WRITER);
#ifdef DEBUG
                for (p = pm_pscc_interest; p; p = p->pscc_next) {
                        /*
                         * Should not be an entry for this clone!
                         */
                        ASSERT(p->pscc_clone != clone);
                }
#endif
                psce = kmem_zalloc(sizeof (psce_t), KM_SLEEP);
                psce->psce_first = kmem_zalloc(sizeof (pm_state_change_t) *
                    PSCCOUNT, KM_SLEEP);
                psce->psce_in = psce->psce_out = psce->psce_first;
                psce->psce_last = &psce->psce_first[PSCCOUNT - 1];
                psce->psce_references = 1;
                pscc->pscc_entries = psce;
                pm_enqueue_pscc(pscc, &pm_pscc_interest);
                pm_interest[clone] = 1;
                rw_exit(&pm_pscc_interest_rwlock);
        }
}

/*
 * Remove the given entry from the blocked list
 */
void
pm_dequeue_blocked(pm_rsvp_t *p)
{
        ASSERT(MUTEX_HELD(&pm_rsvp_lock));
        if (pm_blocked_list == p) {
                ASSERT(p->pr_prev == NULL);
                if (p->pr_next != NULL)
                        p->pr_next->pr_prev = NULL;
                pm_blocked_list = p->pr_next;
        } else {
                ASSERT(p->pr_prev != NULL);
                p->pr_prev->pr_next = p->pr_next;
                if (p->pr_next != NULL)
                        p->pr_next->pr_prev = p->pr_prev;
        }
}

/*
 * Remove the given control struct from the given list
 */
static void
pm_dequeue_pscc(pscc_t *p, pscc_t **list)
{
        if (*list == p) {
                ASSERT(p->pscc_prev == NULL);
                if (p->pscc_next != NULL)
                        p->pscc_next->pscc_prev = NULL;
                *list = p->pscc_next;
        } else {
                ASSERT(p->pscc_prev != NULL);
                p->pscc_prev->pscc_next = p->pscc_next;
                if (p->pscc_next != NULL)
                        p->pscc_next->pscc_prev = p->pscc_prev;
        }
}

/*
 * Stick the control struct specified on the front of the list
 */
static void
pm_enqueue_pscc(pscc_t *p, pscc_t **list)
{
        pscc_t *h;      /* entry at head of list */
        if ((h = *list) == NULL) {
                *list = p;
                ASSERT(p->pscc_next == NULL);
                ASSERT(p->pscc_prev == NULL);
        } else {
                p->pscc_next = h;
                ASSERT(h->pscc_prev == NULL);
                h->pscc_prev = p;
                ASSERT(p->pscc_prev == NULL);
                *list = p;
        }
}

/*
 * If dip is NULL, process is closing "clone" clean up all its registrations.
 * Otherwise only clean up those for dip because process is just giving up
 * control of a direct device.
 */
void
pm_deregister_watcher(int clone, dev_info_t *dip)
{
        pscc_t  *p, *pn;
        psce_t  *psce;
        int found = 0;

        if (dip == NULL) {
                rw_enter(&pm_pscc_interest_rwlock, RW_WRITER);
                for (p = pm_pscc_interest; p; p = pn) {
                        pn = p->pscc_next;
                        if (p->pscc_clone == clone) {
                                pm_dequeue_pscc(p, &pm_pscc_interest);
                                psce = p->pscc_entries;
                                ASSERT(psce->psce_references == 1);
                                mutex_destroy(&psce->psce_lock);
                                kmem_free(psce->psce_first,
                                    sizeof (pm_state_change_t) * PSCCOUNT);
                                kmem_free(psce, sizeof (*psce));
                                kmem_free(p, sizeof (*p));
                        }
                }
                pm_interest[clone] = 0;
                rw_exit(&pm_pscc_interest_rwlock);
        }
        found = 0;
        rw_enter(&pm_pscc_direct_rwlock, RW_WRITER);
        for (p = pm_pscc_direct; p; p = pn) {
                pn = p->pscc_next;
                if ((dip && p->pscc_dip == dip) ||
                    (dip == NULL && clone == p->pscc_clone)) {
                        ASSERT(clone == p->pscc_clone);
                        found++;
                        /*
                         * Remove from control list
                         */
                        pm_dequeue_pscc(p, &pm_pscc_direct);
                        /*
                         * If we're the last reference, free the
                         * entries struct.
                         */
                        psce = p->pscc_entries;
                        ASSERT(psce);
                        if (psce->psce_references == 1) {
                                kmem_free(psce->psce_first,
                                    PSCCOUNT * sizeof (pm_state_change_t));
                                kmem_free(psce, sizeof (*psce));
                        } else {
                                psce->psce_references--;
                        }
                        kmem_free(p, sizeof (*p));
                }
        }
        ASSERT(dip == NULL || found);
        rw_exit(&pm_pscc_direct_rwlock);
}

/*
 * Search the indicated list for an entry that matches clone, and return a
 * pointer to it.  To be interesting, the entry must have something ready to
 * be passed up to the controlling process.
 * The returned entry will be locked upon return from this call.
 */
static psce_t *
pm_psc_find_clone(int clone, pscc_t **list, krwlock_t *lock)
{
        pscc_t  *p;
        psce_t  *psce;
        rw_enter(lock, RW_READER);
        for (p = *list; p; p = p->pscc_next) {
                if (clone == p->pscc_clone) {
                        psce = p->pscc_entries;
                        mutex_enter(&psce->psce_lock);
                        if (psce->psce_out->size) {
                                rw_exit(lock);
                                return (psce);
                        } else {
                                mutex_exit(&psce->psce_lock);
                        }
                }
        }
        rw_exit(lock);
        return (NULL);
}

static psce_t *pm_psc_find_clone(int, pscc_t **, krwlock_t *);
/*
 * Find an entry for a particular clone in the direct list.
 */
psce_t *
pm_psc_clone_to_direct(int clone)
{
        return (pm_psc_find_clone(clone, &pm_pscc_direct,
            &pm_pscc_direct_rwlock));
}

/*
 * Find an entry for a particular clone in the interest list.
 */
psce_t *
pm_psc_clone_to_interest(int clone)
{
        return (pm_psc_find_clone(clone, &pm_pscc_interest,
            &pm_pscc_interest_rwlock));
}

/*
 * Put the given entry at the head of the blocked list
 */
void
pm_enqueue_blocked(pm_rsvp_t *p)
{
        ASSERT(MUTEX_HELD(&pm_rsvp_lock));
        ASSERT(p->pr_next == NULL);
        ASSERT(p->pr_prev == NULL);
        if (pm_blocked_list != NULL) {
                p->pr_next = pm_blocked_list;
                ASSERT(pm_blocked_list->pr_prev == NULL);
                pm_blocked_list->pr_prev = p;
                pm_blocked_list = p;
        } else {
                pm_blocked_list = p;
        }
}

/*
 * Sets every power managed device back to its default threshold
 */
void
pm_all_to_default_thresholds(void)
{
        ddi_walk_devs(ddi_root_node(), pm_set_dev_thr_walk,
            (void *) &pm_system_idle_threshold);
}

static int
pm_set_dev_thr_walk(dev_info_t *dip, void *arg)
{
        int thr = (int)(*(int *)arg);

        if (!PM_GET_PM_INFO(dip))
                return (DDI_WALK_CONTINUE);
        pm_set_device_threshold(dip, thr, PMC_DEF_THRESH);
        return (DDI_WALK_CONTINUE);
}

/*
 * Returns the current threshold value (in seconds) for the indicated component
 */
int
pm_current_threshold(dev_info_t *dip, int comp, int *threshp)
{
        if (comp < 0 || comp >= PM_NUMCMPTS(dip)) {
                return (DDI_FAILURE);
        } else {
                *threshp = cur_threshold(dip, comp);
                return (DDI_SUCCESS);
        }
}

/*
 * To be called when changing the power level of a component of a device.
 * On some platforms, changing power on one device may require that power
 * be changed on other, related devices in the same transaction.  Thus, we
 * always pass this request to the platform power manager so that all the
 * affected devices will be locked.
 */
void
pm_lock_power(dev_info_t *dip, int *circp)
{
        power_req_t power_req;
        int result;

        power_req.request_type = PMR_PPM_LOCK_POWER;
        power_req.req.ppm_lock_power_req.who = dip;
        power_req.req.ppm_lock_power_req.circp = circp;
        (void) pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER, &power_req, &result);
}

/*
 * Release the lock (or locks) acquired to change the power of a device.
 * See comments for pm_lock_power.
 */
void
pm_unlock_power(dev_info_t *dip, int circ)
{
        power_req_t power_req;
        int result;

        power_req.request_type = PMR_PPM_UNLOCK_POWER;
        power_req.req.ppm_unlock_power_req.who = dip;
        power_req.req.ppm_unlock_power_req.circ = circ;
        (void) pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER, &power_req, &result);
}


/*
 * Attempt (without blocking) to acquire the lock(s) needed to change the
 * power of a component of a device.  See comments for pm_lock_power.
 *
 * Return: 1 if lock(s) acquired, 0 if not.
 */
int
pm_try_locking_power(dev_info_t *dip, int *circp)
{
        power_req_t power_req;
        int result;

        power_req.request_type = PMR_PPM_TRY_LOCK_POWER;
        power_req.req.ppm_lock_power_req.who = dip;
        power_req.req.ppm_lock_power_req.circp = circp;
        (void) pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER, &power_req, &result);
        return (result);
}


/*
 * Lock power state of a device.
 *
 * The implementation handles a special case where another thread may have
 * acquired the lock and created/launched this thread to do the work.  If
 * the lock cannot be acquired immediately, we check to see if this thread
 * is registered as a borrower of the lock.  If so, we may proceed without
 * the lock.  This assumes that the lending thread blocks on the completion
 * of this thread.
 *
 * Note 1: for use by ppm only.
 *
 * Note 2: On failing to get the lock immediately, we search lock_loan list
 * for curthread (as borrower of the lock).  On a hit, we check that the
 * lending thread already owns the lock we want.  It is safe to compare
 * devi_busy_thread and thread id of the lender because in the == case (the
 * only one we care about) we know that the owner is blocked.  Similarly,
 * If we find that curthread isn't registered as a lock borrower, it is safe
 * to use the blocking call (ndi_devi_enter) because we know that if we
 * weren't already listed as a borrower (upstream on the call stack) we won't
 * become one.
 */
void
pm_lock_power_single(dev_info_t *dip, int *circp)
{
        lock_loan_t *cur;

        /* if the lock is available, we are done. */
        if (ndi_devi_tryenter(dip, circp))
                return;

        mutex_enter(&pm_loan_lock);
        /* see if our thread is registered as a lock borrower. */
        for (cur = lock_loan_head.pmlk_next; cur; cur = cur->pmlk_next)
                if (cur->pmlk_borrower == curthread)
                        break;
        mutex_exit(&pm_loan_lock);

        /* if this thread not already registered, it is safe to block */
        if (cur == NULL)
                ndi_devi_enter(dip, circp);
        else {
                /* registered: does lender own the lock we want? */
                if (cur->pmlk_lender == DEVI(dip)->devi_busy_thread) {
                        ASSERT(cur->pmlk_dip == NULL || cur->pmlk_dip == dip);
                        cur->pmlk_dip = dip;
                } else /* no: just block for it */
                        ndi_devi_enter(dip, circp);

        }
}

/*
 * Drop the lock on the device's power state.  See comment for
 * pm_lock_power_single() for special implementation considerations.
 *
 * Note: for use by ppm only.
 */
void
pm_unlock_power_single(dev_info_t *dip, int circ)
{
        lock_loan_t *cur;

        /* optimization: mutex not needed to check empty list */
        if (lock_loan_head.pmlk_next == NULL) {
                ndi_devi_exit(dip, circ);
                return;
        }

        mutex_enter(&pm_loan_lock);
        /* see if our thread is registered as a lock borrower. */
        for (cur = lock_loan_head.pmlk_next; cur; cur = cur->pmlk_next)
                if (cur->pmlk_borrower == curthread)
                        break;
        mutex_exit(&pm_loan_lock);

        if (cur == NULL || cur->pmlk_dip != dip)
                /* we acquired the lock directly, so return it */
                ndi_devi_exit(dip, circ);
}

/*
 * Try to take the lock for changing the power level of a component.
 *
 * Note: for use by ppm only.
 */
int
pm_try_locking_power_single(dev_info_t *dip, int *circp)
{
        return (ndi_devi_tryenter(dip, circp));
}

#ifdef  DEBUG
/*
 * The following are used only to print out data structures for debugging
 */
void
prdeps(char *msg)
{

        pm_pdr_t *rp;
        int i;

        pm_log("pm_dep_head %s %p\n", msg, (void *)pm_dep_head);
        for (rp = pm_dep_head; rp; rp = rp->pdr_next) {
                pm_log("%p: %s keeper %s, kept %s, kept count %d, next %p\n",
                    (void *)rp, (rp->pdr_isprop ? "property" : "device"),
                    rp->pdr_keeper, rp->pdr_kept, rp->pdr_kept_count,
                    (void *)rp->pdr_next);
                if (rp->pdr_kept_count != 0) {
                        pm_log("kept list = ");
                        i = 0;
                        while (i < rp->pdr_kept_count) {
                                pm_log("%s ", rp->pdr_kept_paths[i]);
                                i++;
                        }
                        pm_log("\n");
                }
        }
}

void
pr_noinvol(char *hdr)
{
        pm_noinvol_t *ip;

        pm_log("%s\n", hdr);
        rw_enter(&pm_noinvol_rwlock, RW_READER);
        for (ip = pm_noinvol_head; ip; ip = ip->ni_next)
                pm_log("\tmaj %d, flags %x, noinvolpm %d %s\n",
                    ip->ni_major, ip->ni_flags, ip->ni_noinvolpm, ip->ni_path);
        rw_exit(&pm_noinvol_rwlock);
}
#endif

/*
 * Attempt to apply the thresholds indicated by rp to the node specified by
 * dip.
 */
void
pm_apply_recorded_thresh(dev_info_t *dip, pm_thresh_rec_t *rp)
{
        PMD_FUNC(pmf, "apply_recorded_thresh")
        int i, j;
        int comps = PM_NUMCMPTS(dip);
        struct pm_component *cp;
        pm_pte_t *ep;
        int pm_valid_thresh(dev_info_t *, pm_thresh_rec_t *);

        PMD(PMD_THRESH, ("%s: part: %s@%s(%s#%d), rp %p, %s\n", pmf,
            PM_DEVICE(dip), (void *)rp, rp->ptr_physpath))
        PM_LOCK_DIP(dip);
        if (!PM_GET_PM_INFO(dip) || PM_ISBC(dip) || !pm_valid_thresh(dip, rp)) {
                PMD(PMD_FAIL, ("%s: part: %s@%s(%s#%d) PM_GET_PM_INFO %p\n",
                    pmf, PM_DEVICE(dip), (void*)PM_GET_PM_INFO(dip)))
                PMD(PMD_FAIL, ("%s: part: %s@%s(%s#%d) PM_ISBC %d\n",
                    pmf, PM_DEVICE(dip), PM_ISBC(dip)))
                PMD(PMD_FAIL, ("%s: part: %s@%s(%s#%d) pm_valid_thresh %d\n",
                    pmf, PM_DEVICE(dip), pm_valid_thresh(dip, rp)))
                PM_UNLOCK_DIP(dip);
                return;
        }

        ep = rp->ptr_entries;
        /*
         * Here we do the special case of a device threshold
         */
        if (rp->ptr_numcomps == 0) {    /* PM_SET_DEVICE_THRESHOLD product */
                ASSERT(ep && ep->pte_numthresh == 1);
                PMD(PMD_THRESH, ("%s: set dev thr %s@%s(%s#%d) to 0x%x\n",
                    pmf, PM_DEVICE(dip), ep->pte_thresh[0]))
                PM_UNLOCK_DIP(dip);
                pm_set_device_threshold(dip, ep->pte_thresh[0], PMC_DEV_THRESH);
                if (PM_SCANABLE(dip))
                        pm_rescan(dip);
                return;
        }
        for (i = 0; i < comps; i++) {
                cp = PM_CP(dip, i);
                for (j = 0; j < ep->pte_numthresh; j++) {
                        PMD(PMD_THRESH, ("%s: set thr %d for %s@%s(%s#%d)[%d] "
                            "to %x\n", pmf, j, PM_DEVICE(dip),
                            i, ep->pte_thresh[j]))
                        cp->pmc_comp.pmc_thresh[j + 1] = ep->pte_thresh[j];
                }
                ep++;
        }
        DEVI(dip)->devi_pm_flags &= PMC_THRESH_NONE;
        DEVI(dip)->devi_pm_flags |= PMC_COMP_THRESH;
        PM_UNLOCK_DIP(dip);

        if (PM_SCANABLE(dip))
                pm_rescan(dip);
}

/*
 * Returns true if the threshold specified by rp could be applied to dip
 * (that is, the number of components and transitions are the same)
 */
int
pm_valid_thresh(dev_info_t *dip, pm_thresh_rec_t *rp)
{
        PMD_FUNC(pmf, "valid_thresh")
        int comps, i;
        pm_component_t *cp;
        pm_pte_t *ep;

        if (!PM_GET_PM_INFO(dip) || PM_ISBC(dip)) {
                PMD(PMD_ERROR, ("%s: %s: no pm_info or BC\n", pmf,
                    rp->ptr_physpath))
                return (0);
        }
        /*
         * Special case: we represent the PM_SET_DEVICE_THRESHOLD case by
         * an entry with numcomps == 0, (since we don't know how many
         * components there are in advance).  This is always a valid
         * spec.
         */
        if (rp->ptr_numcomps == 0) {
                ASSERT(rp->ptr_entries && rp->ptr_entries->pte_numthresh == 1);
                return (1);
        }
        if (rp->ptr_numcomps != (comps = PM_NUMCMPTS(dip))) {
                PMD(PMD_ERROR, ("%s: comp # mm (dip %d cmd %d) for %s\n",
                    pmf, PM_NUMCMPTS(dip), rp->ptr_numcomps, rp->ptr_physpath))
                return (0);
        }
        ep = rp->ptr_entries;
        for (i = 0; i < comps; i++) {
                cp = PM_CP(dip, i);
                if ((ep + i)->pte_numthresh !=
                    cp->pmc_comp.pmc_numlevels - 1) {
                        PMD(PMD_ERROR, ("%s: %s[%d]: thresh=%d, record=%d\n",
                            pmf, rp->ptr_physpath, i,
                            cp->pmc_comp.pmc_numlevels - 1,
                            (ep + i)->pte_numthresh))
                        return (0);
                }
        }
        return (1);
}

/*
 * Remove any recorded threshold for device physpath
 * We know there will be at most one.
 */
void
pm_unrecord_threshold(char *physpath)
{
        pm_thresh_rec_t *pptr, *ptr;

        rw_enter(&pm_thresh_rwlock, RW_WRITER);
        for (pptr = NULL, ptr = pm_thresh_head; ptr; ptr = ptr->ptr_next) {
                if (strcmp(physpath, ptr->ptr_physpath) == 0) {
                        if (pptr) {
                                pptr->ptr_next = ptr->ptr_next;
                        } else {
                                ASSERT(pm_thresh_head == ptr);
                                pm_thresh_head = ptr->ptr_next;
                        }
                        kmem_free(ptr, ptr->ptr_size);
                        break;
                }
                pptr = ptr;
        }
        rw_exit(&pm_thresh_rwlock);
}

/*
 * Discard all recorded thresholds.  We are returning to the default pm state.
 */
void
pm_discard_thresholds(void)
{
        pm_thresh_rec_t *rp;
        rw_enter(&pm_thresh_rwlock, RW_WRITER);
        while (pm_thresh_head) {
                rp = pm_thresh_head;
                pm_thresh_head = rp->ptr_next;
                kmem_free(rp, rp->ptr_size);
        }
        rw_exit(&pm_thresh_rwlock);
}

/*
 * Discard all recorded dependencies.  We are returning to the default pm state.
 */
void
pm_discard_dependencies(void)
{
        pm_pdr_t *rp;
        int i;
        size_t length;

#ifdef DEBUG
        if (pm_debug & PMD_DEP)
                prdeps("Before discard\n");
#endif
        ddi_walk_devs(ddi_root_node(), pm_discard_dep_walk, NULL);

#ifdef DEBUG
        if (pm_debug & PMD_DEP)
                prdeps("After discard\n");
#endif
        while (pm_dep_head) {
                rp = pm_dep_head;
                if (!rp->pdr_isprop) {
                        ASSERT(rp->pdr_satisfied == 0);
                        ASSERT(pm_unresolved_deps);
                        pm_unresolved_deps--;
                } else {
                        ASSERT(pm_prop_deps);
                        pm_prop_deps--;
                }
                pm_dep_head = rp->pdr_next;
                if (rp->pdr_kept_count)  {
                        for (i = 0; i < rp->pdr_kept_count; i++) {
                                length = strlen(rp->pdr_kept_paths[i]) + 1;
                                kmem_free(rp->pdr_kept_paths[i], length);
                        }
                        kmem_free(rp->pdr_kept_paths,
                            rp->pdr_kept_count * sizeof (char **));
                }
                kmem_free(rp, rp->pdr_size);
        }
}


static int
pm_discard_dep_walk(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))
        char *pathbuf;

        if (PM_GET_PM_INFO(dip) == NULL)
                return (DDI_WALK_CONTINUE);
        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);
        pm_free_keeper(pathbuf, 0);
        kmem_free(pathbuf, MAXPATHLEN);
        return (DDI_WALK_CONTINUE);
}

static int
pm_kept_walk(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))
        char *pathbuf;

        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);
        (void) pm_kept(pathbuf);
        kmem_free(pathbuf, MAXPATHLEN);

        return (DDI_WALK_CONTINUE);
}

static int
pm_keeper_walk(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))
        char *pathbuf;

        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);
        (void) pm_keeper(pathbuf);
        kmem_free(pathbuf, MAXPATHLEN);

        return (DDI_WALK_CONTINUE);
}

static char *
pdw_type_decode(int type)
{
        switch (type) {
        case PM_DEP_WK_POWER_ON:
                return ("power on");
        case PM_DEP_WK_POWER_OFF:
                return ("power off");
        case PM_DEP_WK_DETACH:
                return ("detach");
        case PM_DEP_WK_REMOVE_DEP:
                return ("remove dep");
        case PM_DEP_WK_BRINGUP_SELF:
                return ("bringup self");
        case PM_DEP_WK_RECORD_KEEPER:
                return ("add dependent");
        case PM_DEP_WK_RECORD_KEEPER_PROP:
                return ("add dependent property");
        case PM_DEP_WK_KEPT:
                return ("kept");
        case PM_DEP_WK_KEEPER:
                return ("keeper");
        case PM_DEP_WK_ATTACH:
                return ("attach");
        case PM_DEP_WK_CHECK_KEPT:
                return ("check kept");
        case PM_DEP_WK_CPR_SUSPEND:
                return ("suspend");
        case PM_DEP_WK_CPR_RESUME:
                return ("resume");
        default:
                return ("unknown");
        }

}

static void
pm_rele_dep(char *keeper)
{
        PMD_FUNC(pmf, "rele_dep")
        pm_pdr_t *dp;
        char *kept_path = NULL;
        dev_info_t *kept = NULL;
        int count = 0;

        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (strcmp(dp->pdr_keeper, keeper) != 0)
                        continue;
                for (count = 0; count < dp->pdr_kept_count; count++) {
                        kept_path = dp->pdr_kept_paths[count];
                        if (kept_path == NULL)
                                continue;
                        kept = pm_name_to_dip(kept_path, 1);
                        if (kept) {
                                PMD(PMD_KEEPS, ("%s: release kept=%s@%s(%s#%d) "
                                    "of keeper=%s\n", pmf, PM_DEVICE(kept),
                                    keeper))
                                ASSERT(DEVI(kept)->devi_pm_kidsupcnt > 0);
                                pm_rele_power(kept);
                                ddi_release_devi(kept);
                        }
                }
        }
}

/*
 * Called when we are just released from direct PM.  Bring ourself up
 * if our keeper is up since dependency is not honored while a kept
 * device is under direct PM.
 */
static void
pm_bring_self_up(char *keptpath)
{
        PMD_FUNC(pmf, "bring_self_up")
        dev_info_t *kept;
        dev_info_t *keeper;
        pm_pdr_t *dp;
        int i, j;
        int up = 0, circ;

        kept = pm_name_to_dip(keptpath, 1);
        if (kept == NULL)
                return;
        PMD(PMD_KEEPS, ("%s: kept=%s@%s(%s#%d)\n", pmf, PM_DEVICE(kept)))
        for (dp = pm_dep_head; dp; dp = dp->pdr_next) {
                if (dp->pdr_kept_count == 0)
                        continue;
                for (i = 0; i < dp->pdr_kept_count; i++) {
                        if (strcmp(dp->pdr_kept_paths[i], keptpath) != 0)
                                continue;
                        keeper = pm_name_to_dip(dp->pdr_keeper, 1);
                        if (keeper) {
                                PMD(PMD_KEEPS, ("%s: keeper=%s@%s(%s#%d)\n",
                                    pmf, PM_DEVICE(keeper)))
                                PM_LOCK_POWER(keeper, &circ);
                                for (j = 0; j < PM_NUMCMPTS(keeper);
                                    j++) {
                                        if (PM_CURPOWER(keeper, j)) {
                                                PMD(PMD_KEEPS, ("%s: comp="
                                                    "%d is up\n", pmf, j))
                                                up++;
                                        }
                                }
                                if (up) {
                                        if (PM_SKBU(kept))
                                                DEVI(kept)->devi_pm_flags &=
                                                    ~PMC_SKIP_BRINGUP;
                                        bring_pmdep_up(kept, 1);
                                }
                                PM_UNLOCK_POWER(keeper, circ);
                                ddi_release_devi(keeper);
                        }
                }
        }
        ddi_release_devi(kept);
}

static void
pm_process_dep_request(pm_dep_wk_t *work)
{
        PMD_FUNC(pmf, "dep_req")
        int ret;

        PMD(PMD_DEP, ("%s: work=%s\n", pmf,
            pdw_type_decode(work->pdw_type)))
        PMD(PMD_DEP, ("%s: keeper=%s, kept=%s\n", pmf,
            (work->pdw_keeper ? work->pdw_keeper : "NULL"),
            (work->pdw_kept ? work->pdw_kept : "NULL")))

        switch (work->pdw_type) {
        case PM_DEP_WK_POWER_ON:
                /* Bring up the kept devices and put a hold on them */
                bring_wekeeps_up(work->pdw_keeper);
                break;
        case PM_DEP_WK_POWER_OFF:
                /* Release the kept devices */
                pm_rele_dep(work->pdw_keeper);
                break;
        case PM_DEP_WK_DETACH:
                pm_free_keeps(work->pdw_keeper, work->pdw_pwr);
                break;
        case PM_DEP_WK_REMOVE_DEP:
                pm_discard_dependencies();
                break;
        case PM_DEP_WK_BRINGUP_SELF:
                /*
                 * We deferred satisfying our dependency till now, so satisfy
                 * it again and bring ourselves up.
                 */
                pm_bring_self_up(work->pdw_kept);
                break;
        case PM_DEP_WK_RECORD_KEEPER:
                (void) pm_record_keeper(work->pdw_kept, work->pdw_keeper, 0);
                ddi_walk_devs(ddi_root_node(), pm_kept_walk, NULL);
                ddi_walk_devs(ddi_root_node(), pm_keeper_walk, NULL);
                break;
        case PM_DEP_WK_RECORD_KEEPER_PROP:
                (void) pm_record_keeper(work->pdw_kept, work->pdw_keeper, 1);
                ddi_walk_devs(ddi_root_node(), pm_keeper_walk, NULL);
                ddi_walk_devs(ddi_root_node(), pm_kept_walk, NULL);
                break;
        case PM_DEP_WK_KEPT:
                ret = pm_kept(work->pdw_kept);
                PMD(PMD_DEP, ("%s: PM_DEP_WK_KEPT: pm_kept returns %d\n", pmf,
                    ret))
                break;
        case PM_DEP_WK_KEEPER:
                ret = pm_keeper(work->pdw_keeper);
                PMD(PMD_DEP, ("%s: PM_DEP_WK_KEEPER: pm_keeper returns %d\n",
                    pmf, ret))
                break;
        case PM_DEP_WK_ATTACH:
                ret = pm_keeper(work->pdw_keeper);
                PMD(PMD_DEP, ("%s: PM_DEP_WK_ATTACH: pm_keeper returns %d\n",
                    pmf, ret))
                ret = pm_kept(work->pdw_kept);
                PMD(PMD_DEP, ("%s: PM_DEP_WK_ATTACH: pm_kept returns %d\n",
                    pmf, ret))
                break;
        case PM_DEP_WK_CHECK_KEPT:
                ret = pm_is_kept(work->pdw_kept);
                PMD(PMD_DEP, ("%s: PM_DEP_WK_CHECK_KEPT: kept=%s, ret=%d\n",
                    pmf, work->pdw_kept, ret))
                break;
        case PM_DEP_WK_CPR_SUSPEND:
                pm_discard_dependencies();
                break;
        case PM_DEP_WK_CPR_RESUME:
                ddi_walk_devs(ddi_root_node(), pm_kept_walk, NULL);
                ddi_walk_devs(ddi_root_node(), pm_keeper_walk, NULL);
                break;
        default:
                ASSERT(0);
                break;
        }
        /*
         * Free the work structure if the requester is not waiting
         * Otherwise it is the requester's responsiblity to free it.
         */
        if (!work->pdw_wait) {
                if (work->pdw_keeper)
                        kmem_free(work->pdw_keeper,
                            strlen(work->pdw_keeper) + 1);
                if (work->pdw_kept)
                        kmem_free(work->pdw_kept, strlen(work->pdw_kept) + 1);
                kmem_free(work, sizeof (pm_dep_wk_t));
        } else {
                /*
                 * Notify requester if it is waiting for it.
                 */
                work->pdw_ret = ret;
                work->pdw_done = 1;
                cv_signal(&work->pdw_cv);
        }
}

/*
 * Process PM dependency requests.
 */
static void
pm_dep_thread(void)
{
        pm_dep_wk_t *work;
        callb_cpr_t cprinfo;

        CALLB_CPR_INIT(&cprinfo, &pm_dep_thread_lock, callb_generic_cpr,
            "pm_dep_thread");
        for (;;) {
                mutex_enter(&pm_dep_thread_lock);
                if (pm_dep_thread_workq == NULL) {
                        CALLB_CPR_SAFE_BEGIN(&cprinfo);
                        cv_wait(&pm_dep_thread_cv, &pm_dep_thread_lock);
                        CALLB_CPR_SAFE_END(&cprinfo, &pm_dep_thread_lock);
                }
                work = pm_dep_thread_workq;
                pm_dep_thread_workq = work->pdw_next;
                if (pm_dep_thread_tail == work)
                        pm_dep_thread_tail = work->pdw_next;
                mutex_exit(&pm_dep_thread_lock);
                pm_process_dep_request(work);

        }
        /*NOTREACHED*/
}

/*
 * Set the power level of the indicated device to unknown (if it is not a
 * backwards compatible device), as it has just been resumed, and it won't
 * know if the power was removed or not. Adjust parent's kidsupcnt if necessary.
 */
void
pm_forget_power_level(dev_info_t *dip)
{
        dev_info_t *pdip = ddi_get_parent(dip);
        int i, count = 0;

        if (!PM_ISBC(dip)) {
                for (i = 0; i < PM_NUMCMPTS(dip); i++)
                        count += (PM_CURPOWER(dip, i) == 0);

                if (count && pdip && !PM_WANTS_NOTIFICATION(pdip))
                        e_pm_hold_rele_power(pdip, count);

                /*
                 * Count this as a power cycle if we care
                 */
                if (DEVI(dip)->devi_pm_volpmd &&
                    PM_CP(dip, 0)->pmc_cur_pwr == 0)
                        DEVI(dip)->devi_pm_volpmd = 0;
                for (i = 0; i < PM_NUMCMPTS(dip); i++)
                        e_pm_set_cur_pwr(dip, PM_CP(dip, i), PM_LEVEL_UNKNOWN);
        }
}

/*
 * This function advises the caller whether it should make a power-off
 * transition at this time or not.  If the transition is not advised
 * at this time, the time that the next power-off transition can
 * be made from now is returned through "intervalp" pointer.
 * This function returns:
 *
 *  1  power-off advised
 *  0  power-off not advised, intervalp will point to seconds from
 *        now that a power-off is advised.  If it is passed the number
 *        of years that policy specifies the device should last,
 *        a large number is returned as the time interval.
 *  -1  error
 */
int
pm_trans_check(struct pm_trans_data *datap, time_t *intervalp)
{
        PMD_FUNC(pmf, "pm_trans_check")
        char dbuf[DC_SCSI_MFR_LEN];
        struct pm_scsi_cycles *scp;
        int service_years, service_weeks, full_years;
        time_t now, service_seconds, tdiff;
        time_t within_year, when_allowed;
        char *ptr;
        int lower_bound_cycles, upper_bound_cycles, cycles_allowed;
        int cycles_diff, cycles_over;
        struct pm_smart_count *smart_p;

        if (datap == NULL) {
                PMD(PMD_TCHECK, ("%s: NULL data pointer!\n", pmf))
                return (-1);
        }

        if (datap->format == DC_SCSI_FORMAT) {
                /*
                 * Power cycles of the scsi drives are distributed
                 * over 5 years with the following percentage ratio:
                 *
                 *      30%, 25%, 20%, 15%, and 10%
                 *
                 * The power cycle quota for each year is distributed
                 * linearly through out the year.  The equation for
                 * determining the expected cycles is:
                 *
                 *      e = a * (n / y)
                 *
                 * e = expected cycles
                 * a = allocated cycles for this year
                 * n = number of seconds since beginning of this year
                 * y = number of seconds in a year
                 *
                 * Note that beginning of the year starts the day that
                 * the drive has been put on service.
                 *
                 * If the drive has passed its expected cycles, we
                 * can determine when it can start to power cycle
                 * again to keep it on track to meet the 5-year
                 * life expectancy.  The equation for determining
                 * when to power cycle is:
                 *
                 *      w = y * (c / a)
                 *
                 * w = when it can power cycle again
                 * y = number of seconds in a year
                 * c = current number of cycles
                 * a = allocated cycles for the year
                 *
                 */
                char pcnt[DC_SCSI_NPY] = { 30, 55, 75, 90, 100 };

                scp = &datap->un.scsi_cycles;
                PMD(PMD_TCHECK, ("%s: format=%d, lifemax=%d, ncycles=%d, "
                    "svc_date=%s, svc_flag=%d\n", pmf, datap->format,
                    scp->lifemax, scp->ncycles, scp->svc_date, scp->flag))
                if (scp->ncycles < 0 || scp->flag != 0) {
                        PMD(PMD_TCHECK, ("%s: ncycles < 0 || flag != 0\n", pmf))
                        return (-1);
                }

                if (scp->ncycles > scp->lifemax) {
                        *intervalp = (LONG_MAX / hz);
                        return (0);
                }

                /*
                 * convert service date to time_t
                 */
                bcopy(scp->svc_date, dbuf, DC_SCSI_YEAR_LEN);
                dbuf[DC_SCSI_YEAR_LEN] = '\0';
                ptr = dbuf;
                service_years = stoi(&ptr) - EPOCH_YEAR;
                bcopy(&scp->svc_date[DC_SCSI_YEAR_LEN], dbuf,
                    DC_SCSI_WEEK_LEN);
                dbuf[DC_SCSI_WEEK_LEN] = '\0';

                /*
                 * scsi standard does not specify WW data,
                 * could be (00-51) or (01-52)
                 */
                ptr = dbuf;
                service_weeks = stoi(&ptr);
                if (service_years < 0 ||
                    service_weeks < 0 || service_weeks > 52) {
                        PMD(PMD_TCHECK, ("%s: service year %d and week %d\n",
                            pmf, service_years, service_weeks))
                        return (-1);
                }

                /*
                 * calculate service date in seconds-since-epoch,
                 * adding one day for each leap-year.
                 *
                 * (years-since-epoch + 2) fixes integer truncation,
                 * example: (8) leap-years during [1972, 2000]
                 * (2000 - 1970) = 30;  and  (30 + 2) / 4 = 8;
                 */
                service_seconds = (service_years * DC_SPY) +
                    (service_weeks * DC_SPW) +
                    (((service_years + 2) / 4) * DC_SPD);

                now = gethrestime_sec();
                /*
                 * since the granularity of 'svc_date' is day not second,
                 * 'now' should be rounded up to full day.
                 */
                now = ((now + DC_SPD -1) / DC_SPD) * DC_SPD;
                if (service_seconds > now) {
                        PMD(PMD_TCHECK, ("%s: service date (%ld) later "
                            "than now (%ld)!\n", pmf, service_seconds, now))
                        return (-1);
                }

                tdiff = now - service_seconds;
                PMD(PMD_TCHECK, ("%s: age is %ld sec\n", pmf, tdiff))

                /*
                 * NOTE - Leap years are not considered in the calculations
                 * below.
                 */
                full_years = (tdiff / DC_SPY);
                if ((full_years >= DC_SCSI_NPY) &&
                    (scp->ncycles <= scp->lifemax))
                        return (1);

                /*
                 * Determine what is the normal cycle usage for the
                 * device at the beginning and the end of this year.
                 */
                lower_bound_cycles = (!full_years) ? 0 :
                    ((scp->lifemax * pcnt[full_years - 1]) / 100);
                upper_bound_cycles = (scp->lifemax * pcnt[full_years]) / 100;

                if (scp->ncycles <= lower_bound_cycles)
                        return (1);

                /*
                 * The linear slope that determines how many cycles
                 * are allowed this year is number of seconds
                 * passed this year over total number of seconds in a year.
                 */
                cycles_diff = (upper_bound_cycles - lower_bound_cycles);
                within_year = (tdiff % DC_SPY);
                cycles_allowed = lower_bound_cycles +
                    (((uint64_t)cycles_diff * (uint64_t)within_year) / DC_SPY);
                PMD(PMD_TCHECK, ("%s: lived %d yrs and %ld secs\n", pmf,
                    full_years, within_year))
                PMD(PMD_TCHECK, ("%s: # of cycles allowed %d\n", pmf,
                    cycles_allowed))

                if (scp->ncycles <= cycles_allowed)
                        return (1);

                /*
                 * The transition is not advised now but we can
                 * determine when the next transition can be made.
                 *
                 * Depending on how many cycles the device has been
                 * over-used, we may need to skip years with
                 * different percentage quota in order to determine
                 * when the next transition can be made.
                 */
                cycles_over = (scp->ncycles - lower_bound_cycles);
                while (cycles_over > cycles_diff) {
                        full_years++;
                        if (full_years >= DC_SCSI_NPY) {
                                *intervalp = (LONG_MAX / hz);
                                return (0);
                        }
                        cycles_over -= cycles_diff;
                        lower_bound_cycles = upper_bound_cycles;
                        upper_bound_cycles =
                            (scp->lifemax * pcnt[full_years]) / 100;
                        cycles_diff = (upper_bound_cycles - lower_bound_cycles);
                }

                /*
                 * The linear slope that determines when the next transition
                 * can be made is the relative position of used cycles within a
                 * year over total number of cycles within that year.
                 */
                when_allowed = service_seconds + (full_years * DC_SPY) +
                    (((uint64_t)DC_SPY * (uint64_t)cycles_over) / cycles_diff);
                *intervalp = (when_allowed - now);
                if (*intervalp > (LONG_MAX / hz))
                        *intervalp = (LONG_MAX / hz);
                PMD(PMD_TCHECK, ("%s: no cycle is allowed in %ld secs\n", pmf,
                    *intervalp))
                return (0);
        } else if (datap->format == DC_SMART_FORMAT) {
                /*
                 * power cycles of SATA disks are reported from SMART
                 * attributes.
                 */
                smart_p = &datap->un.smart_count;
                if (smart_p->consumed >= smart_p->allowed) {
                        *intervalp = (LONG_MAX / hz);
                        PMD(PMD_TCHECK, ("%s: exceeded lifemax cycles.\n", pmf))
                        return (0);
                } else
                        return (1);
        }

        PMD(PMD_TCHECK, ("%s: unknown format!\n", pmf))
        return (-1);
}

/*
 * Nexus drivers call into pm framework to indicate which child driver is about
 * to be installed.  In some platforms, ppm may need to configure the hardware
 * for successful installation of a driver.
 */
int
pm_init_child(dev_info_t *dip)
{
        power_req_t power_req;

        ASSERT(ddi_binding_name(dip));
        ASSERT(ddi_get_name_addr(dip));
        pm_ppm_claim(dip);
        if (pm_ppm_claimed(dip)) {      /* if ppm driver claims the node */
                power_req.request_type = PMR_PPM_INIT_CHILD;
                power_req.req.ppm_config_req.who = dip;
                ASSERT(PPM(dip) != NULL);
                return (pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER, &power_req,
                    NULL));
        } else {
#ifdef DEBUG
                /* pass it to the default handler so we can debug things */
                power_req.request_type = PMR_PPM_INIT_CHILD;
                power_req.req.ppm_config_req.who = dip;
                (void) pm_ctlops(NULL, dip,
                    DDI_CTLOPS_POWER, &power_req, NULL);
#endif
        }
        return (DDI_SUCCESS);
}

/*
 * Bring parent of a node that is about to be probed up to full power, and
 * arrange for it to stay up until pm_post_probe() or pm_post_attach() decide
 * it is time to let it go down again
 */
void
pm_pre_probe(dev_info_t *dip, pm_ppm_cookie_t *cp)
{
        int result;
        power_req_t power_req;

        bzero(cp, sizeof (*cp));
        cp->ppc_dip = dip;

        pm_ppm_claim(dip);
        if (pm_ppm_claimed(dip)) {      /* if ppm driver claims the node */
                power_req.request_type = PMR_PPM_PRE_PROBE;
                power_req.req.ppm_config_req.who = dip;
                ASSERT(PPM(dip) != NULL);
                (void) pm_ctlops(PPM(dip), dip,
                    DDI_CTLOPS_POWER, &power_req, &result);
                cp->ppc_ppm = PPM(dip);
        } else {
#ifdef DEBUG
                /* pass it to the default handler so we can debug things */
                power_req.request_type = PMR_PPM_PRE_PROBE;
                power_req.req.ppm_config_req.who = dip;
                (void) pm_ctlops(NULL, dip,
                    DDI_CTLOPS_POWER, &power_req, &result);
#endif
                cp->ppc_ppm = NULL;
        }
}

int
pm_pre_config(dev_info_t *dip, char *devnm)
{
        PMD_FUNC(pmf, "pre_config")
        int ret;

        if (MDI_VHCI(dip)) {
                PMD(PMD_SET, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
                ret = mdi_power(dip, MDI_PM_PRE_CONFIG, NULL, devnm, 0);
                return (ret == MDI_SUCCESS ? DDI_SUCCESS : DDI_FAILURE);
        } else if (!PM_GET_PM_INFO(dip))
                return (DDI_SUCCESS);

        PMD(PMD_SET, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        pm_hold_power(dip);
        ret = pm_all_to_normal(dip, PM_CANBLOCK_BLOCK);
        if (ret != DDI_SUCCESS)
                pm_rele_power(dip);
        return (ret);
}

/*
 * This routine is called by devfs during its walk to unconfigue a node.
 * If the call is due to auto mod_unloads and the dip is not at its
 * full power, we return DDI_FAILURE to terminate the walk, otherwise
 * return DDI_SUCCESS.
 */
int
pm_pre_unconfig(dev_info_t *dip, int flags, int *held, char *devnm)
{
        PMD_FUNC(pmf, "pre_unconfig")
        int ret;

        if (MDI_VHCI(dip)) {
                PMD(PMD_SET, ("%s: %s@%s(%s#%d), flags=%x\n", pmf,
                    PM_DEVICE(dip), flags))
                ret = mdi_power(dip, MDI_PM_PRE_UNCONFIG, held, devnm, flags);
                return (ret == MDI_SUCCESS ? DDI_SUCCESS : DDI_FAILURE);
        } else if (!PM_GET_PM_INFO(dip))
                return (DDI_SUCCESS);

        PMD(PMD_SET, ("%s: %s@%s(%s#%d), flags=%x\n", pmf, PM_DEVICE(dip),
            flags))
        *held = 0;

        /*
         * If the dip is a leaf node, don't power it up.
         */
        if (!ddi_get_child(dip))
                return (DDI_SUCCESS);

        /*
         * Do not power up the node if it is called due to auto-modunload.
         */
        if ((flags & NDI_AUTODETACH) && !pm_all_at_normal(dip))
                return (DDI_FAILURE);

        pm_hold_power(dip);
        *held = 1;
        ret = pm_all_to_normal(dip, PM_CANBLOCK_BLOCK);
        if (ret != DDI_SUCCESS) {
                pm_rele_power(dip);
                *held = 0;
        }
        return (ret);
}

/*
 * Notify ppm of attach action.  Parent is already held at full power by
 * probe action.
 */
void
pm_pre_attach(dev_info_t *dip, pm_ppm_cookie_t *cp, ddi_attach_cmd_t cmd)
{
        static char *me = "pm_pre_attach";
        power_req_t power_req;
        int result;

        /*
         * Initialize and fill in the PPM cookie
         */
        bzero(cp, sizeof (*cp));
        cp->ppc_cmd = (int)cmd;
        cp->ppc_ppm = PPM(dip);
        cp->ppc_dip = dip;

        /*
         * DDI_ATTACH and DDI_RESUME cmds need to call platform specific
         * Power Management stuff. DDI_RESUME also has to purge it's
         * powerlevel information.
         */
        switch (cmd) {
        case DDI_ATTACH:
                if (cp->ppc_ppm) {      /* if ppm driver claims the node */
                        power_req.request_type = PMR_PPM_PRE_ATTACH;
                        power_req.req.ppm_config_req.who = dip;
                        ASSERT(PPM(dip));
                        (void) pm_ctlops(cp->ppc_ppm, dip, DDI_CTLOPS_POWER,
                            &power_req, &result);
                }
#ifdef DEBUG
                else {
                        power_req.request_type = PMR_PPM_PRE_ATTACH;
                        power_req.req.ppm_config_req.who = dip;
                        (void) pm_ctlops(NULL, dip,
                            DDI_CTLOPS_POWER, &power_req, &result);
                }
#endif
                break;
        case DDI_RESUME:
                pm_forget_power_level(dip);

                if (cp->ppc_ppm) {      /* if ppm driver claims the node */
                        power_req.request_type = PMR_PPM_PRE_RESUME;
                        power_req.req.resume_req.who = cp->ppc_dip;
                        power_req.req.resume_req.cmd =
                            (ddi_attach_cmd_t)cp->ppc_cmd;
                        ASSERT(PPM(cp->ppc_dip) == cp->ppc_ppm);
                        (void) pm_ctlops(cp->ppc_ppm, cp->ppc_dip,
                            DDI_CTLOPS_POWER, &power_req, &result);
                }
#ifdef DEBUG
                else {
                        power_req.request_type = PMR_PPM_PRE_RESUME;
                        power_req.req.resume_req.who = cp->ppc_dip;
                        power_req.req.resume_req.cmd =
                            (ddi_attach_cmd_t)cp->ppc_cmd;
                        (void) pm_ctlops(NULL, cp->ppc_dip,
                            DDI_CTLOPS_POWER, &power_req, &result);
                }
#endif
                break;

        case DDI_PM_RESUME:
                break;

        default:
                panic(me);
        }
}

/*
 * Nexus drivers call into pm framework to indicate which child driver is
 * being uninstalled.  In some platforms, ppm may need to reconfigure the
 * hardware since the device driver is no longer installed.
 */
int
pm_uninit_child(dev_info_t *dip)
{
        power_req_t power_req;

        ASSERT(ddi_binding_name(dip));
        ASSERT(ddi_get_name_addr(dip));
        pm_ppm_claim(dip);
        if (pm_ppm_claimed(dip)) {      /* if ppm driver claims the node */
                power_req.request_type = PMR_PPM_UNINIT_CHILD;
                power_req.req.ppm_config_req.who = dip;
                ASSERT(PPM(dip));
                return (pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER, &power_req,
                    NULL));
        } else {
#ifdef DEBUG
                /* pass it to the default handler so we can debug things */
                power_req.request_type = PMR_PPM_UNINIT_CHILD;
                power_req.req.ppm_config_req.who = dip;
                (void) pm_ctlops(NULL, dip, DDI_CTLOPS_POWER, &power_req, NULL);
#endif
        }
        return (DDI_SUCCESS);
}
/*
 * Decrement kidsupcnt so scan can turn the parent back off if it is idle
 * Also notify ppm of result of probe if there is a ppm that cares
 */
void
pm_post_probe(pm_ppm_cookie_t *cp, int ret, int probe_failed)
{
        _NOTE(ARGUNUSED(probe_failed))
        int result;
        power_req_t power_req;

        if (cp->ppc_ppm) {      /* if ppm driver claims the node */
                power_req.request_type = PMR_PPM_POST_PROBE;
                power_req.req.ppm_config_req.who = cp->ppc_dip;
                power_req.req.ppm_config_req.result = ret;
                ASSERT(PPM(cp->ppc_dip) == cp->ppc_ppm);
                (void) pm_ctlops(cp->ppc_ppm, cp->ppc_dip, DDI_CTLOPS_POWER,
                    &power_req, &result);
        }
#ifdef DEBUG
        else {
                power_req.request_type = PMR_PPM_POST_PROBE;
                power_req.req.ppm_config_req.who = cp->ppc_dip;
                power_req.req.ppm_config_req.result = ret;
                (void) pm_ctlops(NULL, cp->ppc_dip, DDI_CTLOPS_POWER,
                    &power_req, &result);
        }
#endif
}

void
pm_post_config(dev_info_t *dip, char *devnm)
{
        PMD_FUNC(pmf, "post_config")

        if (MDI_VHCI(dip)) {
                PMD(PMD_SET, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
                (void) mdi_power(dip, MDI_PM_POST_CONFIG, NULL, devnm, 0);
                return;
        } else if (!PM_GET_PM_INFO(dip))
                return;

        PMD(PMD_SET, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        pm_rele_power(dip);
}

void
pm_post_unconfig(dev_info_t *dip, int held, char *devnm)
{
        PMD_FUNC(pmf, "post_unconfig")

        if (MDI_VHCI(dip)) {
                PMD(PMD_SET, ("%s: %s@%s(%s#%d), held = %d\n", pmf,
                    PM_DEVICE(dip), held))
                (void) mdi_power(dip, MDI_PM_POST_UNCONFIG, &held, devnm, 0);
                return;
        } else if (!PM_GET_PM_INFO(dip))
                return;

        PMD(PMD_SET, ("%s: %s@%s(%s#%d), held = %d\n", pmf, PM_DEVICE(dip),
            held))
        if (!held)
                return;
        /*
         * We have held power in pre_unconfig, release it here.
         */
        pm_rele_power(dip);
}

/*
 * Notify ppm of result of attach if there is a ppm that cares
 */
void
pm_post_attach(pm_ppm_cookie_t *cp, int ret)
{
        int result;
        power_req_t power_req;
        dev_info_t      *dip;

        if (cp->ppc_cmd != DDI_ATTACH)
                return;

        dip = cp->ppc_dip;

        if (ret == DDI_SUCCESS) {
                /*
                 * Attach succeeded, so proceed to doing post-attach pm tasks
                 */
                if (PM_GET_PM_INFO(dip) == NULL)
                        (void) pm_start(dip);
        } else {
                /*
                 * Attach may have got pm started before failing
                 */
                pm_stop(dip);
        }

        if (cp->ppc_ppm) {      /* if ppm driver claims the node */
                power_req.request_type = PMR_PPM_POST_ATTACH;
                power_req.req.ppm_config_req.who = cp->ppc_dip;
                power_req.req.ppm_config_req.result = ret;
                ASSERT(PPM(cp->ppc_dip) == cp->ppc_ppm);
                (void) pm_ctlops(cp->ppc_ppm, cp->ppc_dip,
                    DDI_CTLOPS_POWER, &power_req, &result);
        }
#ifdef DEBUG
        else {
                power_req.request_type = PMR_PPM_POST_ATTACH;
                power_req.req.ppm_config_req.who = cp->ppc_dip;
                power_req.req.ppm_config_req.result = ret;
                (void) pm_ctlops(NULL, cp->ppc_dip,
                    DDI_CTLOPS_POWER, &power_req, &result);
        }
#endif
}

/*
 * Notify ppm of attach action.  Parent is already held at full power by
 * probe action.
 */
void
pm_pre_detach(dev_info_t *dip, ddi_detach_cmd_t cmd, pm_ppm_cookie_t *cp)
{
        int result;
        power_req_t power_req;

        bzero(cp, sizeof (*cp));
        cp->ppc_dip = dip;
        cp->ppc_cmd = (int)cmd;

        switch (cmd) {
        case DDI_DETACH:
                pm_detaching(dip);              /* suspend pm while detaching */
                if (pm_ppm_claimed(dip)) {      /* if ppm driver claims node */
                        power_req.request_type = PMR_PPM_PRE_DETACH;
                        power_req.req.ppm_config_req.who = dip;
                        ASSERT(PPM(dip));
                        (void) pm_ctlops(PPM(dip), dip, DDI_CTLOPS_POWER,
                            &power_req, &result);
                        cp->ppc_ppm = PPM(dip);
                } else {
#ifdef DEBUG
                        /* pass to the default handler so we can debug things */
                        power_req.request_type = PMR_PPM_PRE_DETACH;
                        power_req.req.ppm_config_req.who = dip;
                        (void) pm_ctlops(NULL, dip,
                            DDI_CTLOPS_POWER, &power_req, &result);
#endif
                        cp->ppc_ppm = NULL;
                }
                break;

        default:
                break;
        }
}

/*
 * Dip is either a leaf node that exported "no-involuntary-power-cycles" prop.,
 * (if devi_pm_noinvol count is 0) or an ancestor of such a node.  We need to
 * make an entry to record the details, which includes certain flag settings.
 */
static void
pm_record_invol_path(char *path, int flags, int noinvolpm, int volpmd,
    int wasvolpmd, major_t major)
{
        PMD_FUNC(pmf, "record_invol_path")
        major_t pm_path_to_major(char *);
        size_t plen;
        pm_noinvol_t *ip, *np, *pp;
        pp = NULL;

        plen = strlen(path) + 1;
        np = kmem_zalloc(sizeof (*np), KM_SLEEP);
        np->ni_size = plen;
        np->ni_path = kmem_alloc(plen, KM_SLEEP);
        np->ni_noinvolpm = noinvolpm;
        np->ni_volpmd = volpmd;
        np->ni_wasvolpmd = wasvolpmd;
        np->ni_flags = flags;
        (void) strcpy(np->ni_path, path);
        /*
         * If we haven't actually seen the node attached, it is hard to figure
         * out its major.  If we could hold the node by path, we would be much
         * happier here.
         */
        if (major == DDI_MAJOR_T_NONE) {
                np->ni_major = pm_path_to_major(path);
        } else {
                np->ni_major = major;
        }
        rw_enter(&pm_noinvol_rwlock, RW_WRITER);
        for (ip = pm_noinvol_head; ip; pp = ip, ip = ip->ni_next) {
                int comp = strcmp(path, ip->ni_path);
                if (comp < 0) {
                        PMD(PMD_NOINVOL, ("%s: %s insert before %s\n",
                            pmf, path, ip->ni_path))
                        /* insert before current entry */
                        np->ni_next = ip;
                        if (pp) {
                                pp->ni_next = np;
                        } else {
                                pm_noinvol_head = np;
                        }
                        rw_exit(&pm_noinvol_rwlock);
#ifdef DEBUG
                        if (pm_debug & PMD_NOINVOL)
                                pr_noinvol("record_invol_path exit0");
#endif
                        return;
                } else if (comp == 0) {
                        panic("%s already in pm_noinvol list", path);
                }
        }
        /*
         * If we did not find an entry in the list that this should go before,
         * then it must go at the end
         */
        if (pp) {
                PMD(PMD_NOINVOL, ("%s: %s append after %s\n", pmf, path,
                    pp->ni_path))
                ASSERT(pp->ni_next == 0);
                pp->ni_next = np;
        } else {
                PMD(PMD_NOINVOL, ("%s: %s added to end-of-list\n", pmf, path))
                ASSERT(!pm_noinvol_head);
                pm_noinvol_head = np;
        }
        rw_exit(&pm_noinvol_rwlock);
#ifdef DEBUG
        if (pm_debug & PMD_NOINVOL)
                pr_noinvol("record_invol_path exit");
#endif
}

void
pm_record_invol(dev_info_t *dip)
{
        char *pathbuf;
        int pm_all_components_off(dev_info_t *);
        int volpmd = (PM_NUMCMPTS(dip) > 0) && pm_all_components_off(dip);

        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);

        pm_record_invol_path(pathbuf, (DEVI(dip)->devi_pm_flags &
            (PMC_NO_INVOL | PMC_CONSOLE_FB)), DEVI(dip)->devi_pm_noinvolpm,
            DEVI(dip)->devi_pm_volpmd, volpmd, PM_MAJOR(dip));

        /*
         * If this child's detach will be holding up its ancestors, then we
         * allow for an exception to that if all children of this type have
         * gone down voluntarily.
         * Now walk down the tree incrementing devi_pm_noinvolpm
         */
        (void) pm_noinvol_update(PM_BP_NOINVOL_DETACH, 0, volpmd, pathbuf,
            dip);
        kmem_free(pathbuf, MAXPATHLEN);
}

void
pm_post_detach(pm_ppm_cookie_t *cp, int ret)
{
        dev_info_t *dip = cp->ppc_dip;
        int result;
        power_req_t power_req;

        switch (cp->ppc_cmd) {
        case DDI_DETACH:
                if (cp->ppc_ppm) {      /* if ppm driver claims the node */
                        power_req.request_type = PMR_PPM_POST_DETACH;
                        power_req.req.ppm_config_req.who = cp->ppc_dip;
                        power_req.req.ppm_config_req.result = ret;
                        ASSERT(PPM(cp->ppc_dip) == cp->ppc_ppm);
                        (void) pm_ctlops(cp->ppc_ppm, cp->ppc_dip,
                            DDI_CTLOPS_POWER, &power_req, &result);
                }
#ifdef DEBUG
                else {
                        power_req.request_type = PMR_PPM_POST_DETACH;
                        power_req.req.ppm_config_req.who = cp->ppc_dip;
                        power_req.req.ppm_config_req.result = ret;
                        (void) pm_ctlops(NULL, cp->ppc_dip,
                            DDI_CTLOPS_POWER, &power_req, &result);
                }
#endif
                if (ret == DDI_SUCCESS) {
                        /*
                         * For hotplug detach we assume it is *really* gone
                         */
                        if (cp->ppc_cmd == DDI_DETACH &&
                            ((DEVI(dip)->devi_pm_flags &
                            (PMC_NO_INVOL | PMC_CONSOLE_FB)) ||
                            DEVI(dip)->devi_pm_noinvolpm))
                                pm_record_invol(dip);
                        DEVI(dip)->devi_pm_flags &=
                            ~(PMC_NO_INVOL | PMC_NOINVOL_DONE);

                        /*
                         * If console fb is detaching, then we don't need to
                         * worry any more about it going off (pm_detaching has
                         * brought up all components)
                         */
                        if (PM_IS_CFB(dip)) {
                                mutex_enter(&pm_cfb_lock);
                                ASSERT(cfb_dip_detaching);
                                ASSERT(cfb_dip == NULL);
                                ASSERT(pm_cfb_comps_off == 0);
                                cfb_dip_detaching = NULL;
                                mutex_exit(&pm_cfb_lock);
                        }
                        pm_stop(dip);   /* make it permanent */
                } else {
                        if (PM_IS_CFB(dip)) {
                                mutex_enter(&pm_cfb_lock);
                                ASSERT(cfb_dip_detaching);
                                ASSERT(cfb_dip == NULL);
                                ASSERT(pm_cfb_comps_off == 0);
                                cfb_dip = cfb_dip_detaching;
                                cfb_dip_detaching = NULL;
                                mutex_exit(&pm_cfb_lock);
                        }
                        pm_detach_failed(dip);  /* resume power management */
                }
                break;
        case DDI_PM_SUSPEND:
                break;
        case DDI_SUSPEND:
                break;                          /* legal, but nothing to do */
        default:
#ifdef DEBUG
                panic("pm_post_detach: unrecognized cmd %d for detach",
                    cp->ppc_cmd);
                /*NOTREACHED*/
#else
                break;
#endif
        }
}

/*
 * Called after vfs_mountroot has got the clock started to fix up timestamps
 * that were set when root bush drivers attached.  hresttime was 0 then, so the
 * devices look busy but have a 0 busycnt
 */
int
pm_adjust_timestamps(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))

        pm_info_t *info = PM_GET_PM_INFO(dip);
        struct pm_component *cp;
        int i;

        if (!info)
                return (DDI_WALK_CONTINUE);
        PM_LOCK_BUSY(dip);
        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                cp = PM_CP(dip, i);
                if (cp->pmc_timestamp == 0 && cp->pmc_busycount == 0)
                        cp->pmc_timestamp = gethrestime_sec();
        }
        PM_UNLOCK_BUSY(dip);
        return (DDI_WALK_CONTINUE);
}

/*
 * Called at attach time to see if the device being attached has a record in
 * the no involuntary power cycles list.  If so, we do some bookkeeping on the
 * parents and set a flag in the dip
 */
void
pm_noinvol_specd(dev_info_t *dip)
{
        PMD_FUNC(pmf, "noinvol_specd")
        char *pathbuf;
        pm_noinvol_t *ip, *pp = NULL;
        int wasvolpmd;
        int found = 0;

        if (DEVI(dip)->devi_pm_flags & PMC_NOINVOL_DONE)
                return;
        DEVI(dip)->devi_pm_flags |=  PMC_NOINVOL_DONE;
        pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
        (void) ddi_pathname(dip, pathbuf);

        PM_LOCK_DIP(dip);
        DEVI(dip)->devi_pm_volpmd = 0;
        DEVI(dip)->devi_pm_noinvolpm = 0;
        rw_enter(&pm_noinvol_rwlock, RW_READER);
        for (ip = pm_noinvol_head; ip; pp = ip, ip = ip->ni_next) {
                PMD(PMD_NOINVOL, ("%s: comparing '%s' to '%s'\n",
                    pmf, pathbuf, ip->ni_path))
                if (strcmp(pathbuf, ip->ni_path) == 0) {
                        found++;
                        break;
                }
        }
        rw_exit(&pm_noinvol_rwlock);
        if (!found) {
                PM_UNLOCK_DIP(dip);
                kmem_free(pathbuf, MAXPATHLEN);
                return;
        }
        rw_enter(&pm_noinvol_rwlock, RW_WRITER);
        pp = NULL;
        for (ip = pm_noinvol_head; ip; pp = ip, ip = ip->ni_next) {
                PMD(PMD_NOINVOL, ("%s: comparing '%s' to '%s'\n",
                    pmf, pathbuf, ip->ni_path))
                if (strcmp(pathbuf, ip->ni_path) == 0) {
                        ip->ni_flags &= ~PMC_DRIVER_REMOVED;
                        DEVI(dip)->devi_pm_flags |= ip->ni_flags;
                        /*
                         * Handle special case of console fb
                         */
                        if (PM_IS_CFB(dip)) {
                                mutex_enter(&pm_cfb_lock);
                                cfb_dip = dip;
                                PMD(PMD_CFB, ("%s: %s@%s(%s#%d) setting "
                                    "cfb_dip\n", pmf, PM_DEVICE(dip)))
                                mutex_exit(&pm_cfb_lock);
                        }
                        DEVI(dip)->devi_pm_noinvolpm = ip->ni_noinvolpm;
                        ASSERT((DEVI(dip)->devi_pm_flags &
                            (PMC_NO_INVOL | PMC_CONSOLE_FB)) ||
                            DEVI(dip)->devi_pm_noinvolpm);
                        DEVI(dip)->devi_pm_volpmd = ip->ni_volpmd;
                        PMD(PMD_NOINVOL, ("%s: noinvol=%d, volpmd=%d, "
                            "wasvolpmd=%d, flags=%x, path=%s\n", pmf,
                            ip->ni_noinvolpm, ip->ni_volpmd,
                            ip->ni_wasvolpmd, ip->ni_flags, ip->ni_path))
                        /*
                         * free the entry in hopes the list will now be empty
                         * and we won't have to search it any more until the
                         * device detaches
                         */
                        if (pp) {
                                PMD(PMD_NOINVOL, ("%s: free %s, prev %s\n",
                                    pmf, ip->ni_path, pp->ni_path))
                                pp->ni_next = ip->ni_next;
                        } else {
                                PMD(PMD_NOINVOL, ("%s: free %s head\n",
                                    pmf, ip->ni_path))
                                ASSERT(pm_noinvol_head == ip);
                                pm_noinvol_head = ip->ni_next;
                        }
                        PM_UNLOCK_DIP(dip);
                        wasvolpmd = ip->ni_wasvolpmd;
                        rw_exit(&pm_noinvol_rwlock);
                        kmem_free(ip->ni_path, ip->ni_size);
                        kmem_free(ip, sizeof (*ip));
                        /*
                         * Now walk up the tree decrementing devi_pm_noinvolpm
                         * (and volpmd if appropriate)
                         */
                        (void) pm_noinvol_update(PM_BP_NOINVOL_ATTACH, 0,
                            wasvolpmd, pathbuf, dip);
#ifdef DEBUG
                        if (pm_debug & PMD_NOINVOL)
                                pr_noinvol("noinvol_specd exit");
#endif
                        kmem_free(pathbuf, MAXPATHLEN);
                        return;
                }
        }
        kmem_free(pathbuf, MAXPATHLEN);
        rw_exit(&pm_noinvol_rwlock);
        PM_UNLOCK_DIP(dip);
}

int
pm_all_components_off(dev_info_t *dip)
{
        int i;
        pm_component_t *cp;

        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                cp = PM_CP(dip, i);
                if (cp->pmc_cur_pwr == PM_LEVEL_UNKNOWN ||
                    cp->pmc_comp.pmc_lvals[cp->pmc_cur_pwr])
                        return (0);
        }
        return (1);     /* all off */
}

/*
 * Make sure that all "no involuntary power cycles" devices are attached.
 * Called before doing a cpr suspend to make sure the driver has a say about
 * the power cycle
 */
int
pm_reattach_noinvol(void)
{
        PMD_FUNC(pmf, "reattach_noinvol")
        pm_noinvol_t *ip;
        char *path;
        dev_info_t *dip;

        /*
         * Prevent the modunload thread from unloading any modules until we
         * have completely stopped all kernel threads.
         */
        modunload_disable();
        for (ip = pm_noinvol_head; ip; ip = ip->ni_next) {
                /*
                 * Forget we'v ever seen any entry
                 */
                ip->ni_persistent = 0;
        }
restart:
        rw_enter(&pm_noinvol_rwlock, RW_READER);
        for (ip = pm_noinvol_head; ip; ip = ip->ni_next) {
#ifdef PMDDEBUG
                major_t maj;
                maj = ip->ni_major;
#endif
                path = ip->ni_path;
                if (path != NULL && !(ip->ni_flags & PMC_DRIVER_REMOVED)) {
                        if (ip->ni_persistent) {
                                /*
                                 * If we weren't able to make this entry
                                 * go away, then we give up, as
                                 * holding/attaching the driver ought to have
                                 * resulted in this entry being deleted
                                 */
                                PMD(PMD_NOINVOL, ("%s: can't reattach %s "
                                    "(%s|%d)\n", pmf, ip->ni_path,
                                    ddi_major_to_name(maj), (int)maj))
                                cmn_err(CE_WARN, "cpr: unable to reattach %s ",
                                    ip->ni_path);
                                modunload_enable();
                                rw_exit(&pm_noinvol_rwlock);
                                return (0);
                        }
                        ip->ni_persistent++;
                        rw_exit(&pm_noinvol_rwlock);
                        PMD(PMD_NOINVOL, ("%s: holding %s\n", pmf, path))
                        dip = e_ddi_hold_devi_by_path(path, 0);
                        if (dip == NULL) {
                                PMD(PMD_NOINVOL, ("%s: can't hold (%s|%d)\n",
                                    pmf, path, (int)maj))
                                cmn_err(CE_WARN, "cpr: unable to hold %s "
                                    "driver", path);
                                modunload_enable();
                                return (0);
                        } else {
                                PMD(PMD_DHR, ("%s: release %s\n", pmf, path))
                                /*
                                 * Since the modunload thread is stopped, we
                                 * don't have to keep the driver held, which
                                 * saves a ton of bookkeeping
                                 */
                                ddi_release_devi(dip);
                                goto restart;
                        }
                } else {
                        PMD(PMD_NOINVOL, ("%s: skip %s; unknown major\n",
                            pmf, ip->ni_path))
                        continue;
                }
        }
        rw_exit(&pm_noinvol_rwlock);
        return (1);
}

void
pm_reattach_noinvol_fini(void)
{
        modunload_enable();
}

/*
 * Display pm support code
 */


/*
 * console frame-buffer power-mgmt gets enabled when debugging
 * services are not present or console fbpm override is set
 */
void
pm_cfb_setup(const char *stdout_path)
{
        PMD_FUNC(pmf, "cfb_setup")
        extern int obpdebug;
        char *devname;
        dev_info_t *dip;
        int devname_len;
        extern dev_info_t *fbdip;

        /*
         * By virtue of this function being called (from consconfig),
         * we know stdout is a framebuffer.
         */
        stdout_is_framebuffer = 1;

        if (obpdebug || (boothowto & RB_DEBUG)) {
                if (pm_cfb_override == 0) {
                        /*
                         * Console is frame buffer, but we want to suppress
                         * pm on it because of debugging setup
                         */
                        pm_cfb_enabled = 0;
                        cmn_err(CE_NOTE, "Kernel debugger present: disabling "
                            "console power management.");
                        /*
                         * however, we still need to know which is the console
                         * fb in order to suppress pm on it
                         */
                } else {
                        cmn_err(CE_WARN, "Kernel debugger present: see "
                            "kmdb(1M) for interaction with power management.");
                }
        }
#ifdef DEBUG
        /*
         * IF console is fb and is power managed, don't do prom_printfs from
         * pm debug macro
         */
        if (pm_cfb_enabled && !pm_debug_to_console) {
                if (pm_debug)
                        prom_printf("pm debug output will be to log only\n");
                pm_divertdebug++;
        }
#endif
        devname = i_ddi_strdup((char *)stdout_path, KM_SLEEP);
        devname_len = strlen(devname) + 1;
        PMD(PMD_CFB, ("%s: stripped %s\n", pmf, devname))
        /* if the driver is attached */
        if ((dip = fbdip) != NULL) {
                PMD(PMD_CFB, ("%s: attached: %s@%s(%s#%d)\n", pmf,
                    PM_DEVICE(dip)))
                /*
                 * We set up here as if the driver were power manageable in case
                 * we get a later attach of a pm'able driver (which would result
                 * in a panic later)
                 */
                cfb_dip = dip;
                DEVI(dip)->devi_pm_flags |= (PMC_CONSOLE_FB | PMC_NO_INVOL);
                PMD(PMD_CFB, ("%s: cfb_dip -> %s@%s(%s#%d)\n", pmf,
                    PM_DEVICE(dip)))
#ifdef DEBUG
                if (!(PM_GET_PM_INFO(dip) != NULL && PM_NUMCMPTS(dip))) {
                        PMD(PMD_CFB, ("%s: %s@%s(%s#%d) not power-managed\n",
                            pmf, PM_DEVICE(dip)))
                }
#endif
        } else {
                char *ep;
                PMD(PMD_CFB, ("%s: pntd %s failed\n", pmf, devname))
                pm_record_invol_path(devname,
                    (PMC_CONSOLE_FB | PMC_NO_INVOL), 1, 0, 0,
                    DDI_MAJOR_T_NONE);
                for (ep = strrchr(devname, '/'); ep != devname;
                    ep = strrchr(devname, '/')) {
                        PMD(PMD_CFB, ("%s: devname %s\n", pmf, devname))
                        *ep = '\0';
                        dip = pm_name_to_dip(devname, 0);
                        if (dip != NULL) {
                                /*
                                 * Walk up the tree incrementing
                                 * devi_pm_noinvolpm
                                 */
                                (void) pm_noinvol_update(PM_BP_NOINVOL_CFB,
                                    0, 0, devname, dip);
                                break;
                        } else {
                                pm_record_invol_path(devname,
                                    PMC_NO_INVOL, 1, 0, 0, DDI_MAJOR_T_NONE);
                        }
                }
        }
        kmem_free(devname, devname_len);
}

void
pm_cfb_rele(void)
{
        mutex_enter(&pm_cfb_lock);
        /*
         * this call isn't using the console any  more, it is ok to take it
         * down if the count goes to 0
         */
        cfb_inuse--;
        mutex_exit(&pm_cfb_lock);
}

/*
 * software interrupt handler for fbpm; this function exists because we can't
 * bring up the frame buffer power from above lock level.  So if we need to,
 * we instead schedule a softint that runs this routine and takes us into
 * debug_enter (a bit delayed from the original request, but avoiding a panic).
 */
static uint_t
pm_cfb_softint(caddr_t int_handler_arg)
{
        _NOTE(ARGUNUSED(int_handler_arg))
        int rval = DDI_INTR_UNCLAIMED;

        mutex_enter(&pm_cfb_lock);
        if (pm_soft_pending) {
                mutex_exit(&pm_cfb_lock);
                debug_enter((char *)NULL);
                /* acquired in debug_enter before calling pm_cfb_trigger */
                pm_cfb_rele();
                mutex_enter(&pm_cfb_lock);
                pm_soft_pending = B_FALSE;
                mutex_exit(&pm_cfb_lock);
                rval = DDI_INTR_CLAIMED;
        } else
                mutex_exit(&pm_cfb_lock);

        return (rval);
}

void
pm_cfb_setup_intr(void)
{
        PMD_FUNC(pmf, "cfb_setup_intr")
        extern void prom_set_outfuncs(void (*)(void), void (*)(void));
        void pm_cfb_check_and_powerup(void);

        mutex_init(&pm_cfb_lock, NULL, MUTEX_SPIN, (void *)ipltospl(SPL8));
#ifdef PMDDEBUG
        mutex_init(&pm_debug_lock, NULL, MUTEX_SPIN, (void *)ipltospl(SPL8));
#endif

        if (!stdout_is_framebuffer) {
                PMD(PMD_CFB, ("%s: console not fb\n", pmf))
                return;
        }

        /*
         * setup software interrupt handler
         */
        if (ddi_add_softintr(ddi_root_node(), DDI_SOFTINT_HIGH, &pm_soft_id,
            NULL, NULL, pm_cfb_softint, NULL) != DDI_SUCCESS)
                panic("pm: unable to register soft intr.");

        prom_set_outfuncs(pm_cfb_check_and_powerup, pm_cfb_rele);
}

/*
 * Checks to see if it is safe to write to the console wrt power management
 * (i.e. if the console is a framebuffer, then it must be at full power)
 * returns 1 when power is off (power-up is needed)
 * returns 0 when power is on (power-up not needed)
 */
int
pm_cfb_check_and_hold(void)
{
        /*
         * cfb_dip is set iff console is a power manageable frame buffer
         * device
         */
        extern int modrootloaded;

        mutex_enter(&pm_cfb_lock);
        cfb_inuse++;
        ASSERT(cfb_inuse);      /* wrap? */
        if (modrootloaded && cfb_dip) {
                /*
                 * don't power down the frame buffer, the prom is using it
                 */
                if (pm_cfb_comps_off) {
                        mutex_exit(&pm_cfb_lock);
                        return (1);
                }
        }
        mutex_exit(&pm_cfb_lock);
        return (0);
}

/*
 * turn on cfb power (which is known to be off).
 * Must be called below lock level!
 */
void
pm_cfb_powerup(void)
{
        pm_info_t *info;
        int norm;
        int ccount, ci;
        int unused;
#ifdef DEBUG
        /*
         * Can't reenter prom_prekern, so suppress pm debug messages
         * (still go to circular buffer).
         */
        mutex_enter(&pm_debug_lock);
        pm_divertdebug++;
        mutex_exit(&pm_debug_lock);
#endif
        info = PM_GET_PM_INFO(cfb_dip);
        ASSERT(info);

        ccount = PM_NUMCMPTS(cfb_dip);
        for (ci = 0; ci < ccount; ci++) {
                norm = pm_get_normal_power(cfb_dip, ci);
                (void) pm_set_power(cfb_dip, ci, norm, PM_LEVEL_UPONLY,
                    PM_CANBLOCK_BYPASS, 0, &unused);
        }
#ifdef DEBUG
        mutex_enter(&pm_debug_lock);
        pm_divertdebug--;
        mutex_exit(&pm_debug_lock);
#endif
}

/*
 * Check if the console framebuffer is powered up.  If not power it up.
 * Note: Calling pm_cfb_check_and_hold has put a hold on the power state which
 * must be released by calling pm_cfb_rele when the console fb operation
 * is completed.
 */
void
pm_cfb_check_and_powerup(void)
{
        if (pm_cfb_check_and_hold())
                pm_cfb_powerup();
}

/*
 * Trigger a low level interrupt to power up console frame buffer.
 */
void
pm_cfb_trigger(void)
{
        if (cfb_dip == NULL)
                return;

        mutex_enter(&pm_cfb_lock);
        /*
         * If the machine appears to be hung, pulling the keyboard connector of
         * the console will cause a high level interrupt and go to debug_enter.
         * But, if the fb is powered down, this routine will be called to bring
         * it up (by generating a softint to do the work). If a second attempt
         * at triggering this softint happens before the first one completes,
         * we panic as softints are most likely not being handled.
         */
        if (pm_soft_pending) {
                panicstr = "pm_cfb_trigger: failed to enter the debugger";
                panic(panicstr);        /* does a power up at any intr level */
                /* NOTREACHED */
        }
        pm_soft_pending = B_TRUE;
        mutex_exit(&pm_cfb_lock);
        ddi_trigger_softintr(pm_soft_id);
}

static major_t i_path_to_major(char *, char *);

major_t
pm_path_to_major(char *path)
{
        PMD_FUNC(pmf, "path_to_major")
        char *np, *ap, *bp;
        major_t ret;
        size_t len;

        PMD(PMD_NOINVOL, ("%s: %s\n", pmf, path))

        np = strrchr(path, '/');
        if (np != NULL)
                np++;
        else
                np = path;
        len = strlen(np) + 1;
        bp = kmem_alloc(len, KM_SLEEP);
        (void) strcpy(bp, np);
        if ((ap = strchr(bp, '@')) != NULL) {
                *ap = '\0';
        }
        PMD(PMD_NOINVOL, ("%s: %d\n", pmf, ddi_name_to_major(np)))
        ret = i_path_to_major(path, np);
        kmem_free(bp, len);
        return (ret);
}

#ifdef DEBUG
#ifndef sparc
clock_t pt_sleep = 1;
#endif

char    *pm_msgp;
char    *pm_bufend;
char    *pm_msgbuf = NULL;
int     pm_logpages = 0x100;
#include <sys/sunldi.h>
#include <sys/uio.h>
clock_t pm_log_sleep = 1000;
int     pm_extra_cr = 1;
volatile int pm_tty = 1;

#define PMLOGPGS        pm_logpages

#if defined(__x86)
void pm_printf(char *s);
#endif

/*PRINTFLIKE1*/
void
pm_log(const char *fmt, ...)
{
        va_list adx;
        size_t size;

        mutex_enter(&pm_debug_lock);
        if (pm_msgbuf == NULL) {
                pm_msgbuf = kmem_zalloc(mmu_ptob(PMLOGPGS), KM_SLEEP);
                pm_bufend = pm_msgbuf + mmu_ptob(PMLOGPGS) - 1;
                pm_msgp = pm_msgbuf;
        }
        va_start(adx, fmt);
        size = vsnprintf(NULL, 0, fmt, adx) + 1;
        va_end(adx);
        va_start(adx, fmt);
        if (size > (pm_bufend - pm_msgp)) {             /* wraps */
                bzero(pm_msgp, pm_bufend - pm_msgp);
                (void) vsnprintf(pm_msgbuf, size, fmt, adx);
                if (!pm_divertdebug)
                        prom_printf("%s", pm_msgp);
#if defined(__x86)
                if (pm_tty) {
                        pm_printf(pm_msgp);
                        if (pm_extra_cr)
                                pm_printf("\r");
                }
#endif
                pm_msgp = pm_msgbuf + size;
        } else {
                (void) vsnprintf(pm_msgp, size, fmt, adx);
#if defined(__x86)
                if (pm_tty) {
                        pm_printf(pm_msgp);
                        if (pm_extra_cr)
                                pm_printf("\r");
                }
#endif
                if (!pm_divertdebug)
                        prom_printf("%s", pm_msgp);
                pm_msgp += size;
        }
        va_end(adx);
        mutex_exit(&pm_debug_lock);
        drv_usecwait((clock_t)pm_log_sleep);
}
#endif  /* DEBUG */

/*
 * We want to save the state of any directly pm'd devices over the suspend/
 * resume process so that we can put them back the way the controlling
 * process left them.
 */
void
pm_save_direct_levels(void)
{
        pm_processes_stopped = 1;
        ddi_walk_devs(ddi_root_node(), pm_save_direct_lvl_walk, 0);
}

static int
pm_save_direct_lvl_walk(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))
        int i;
        int *ip;
        pm_info_t *info = PM_GET_PM_INFO(dip);

        if (!info)
                return (DDI_WALK_CONTINUE);

        if (PM_ISDIRECT(dip) && !PM_ISBC(dip)) {
                if (PM_NUMCMPTS(dip) > 2) {
                        info->pmi_lp = kmem_alloc(PM_NUMCMPTS(dip) *
                            sizeof (int), KM_SLEEP);
                        ip = info->pmi_lp;
                } else {
                        ip = info->pmi_levels;
                }
                /* autopm and processes are stopped, ok not to lock power */
                for (i = 0; i < PM_NUMCMPTS(dip); i++)
                        *ip++ = PM_CURPOWER(dip, i);
                /*
                 * There is a small window between stopping the
                 * processes and setting pm_processes_stopped where
                 * a driver could get hung up in a pm_raise_power()
                 * call.  Free any such driver now.
                 */
                pm_proceed(dip, PMP_RELEASE, -1, -1);
        }

        return (DDI_WALK_CONTINUE);
}

void
pm_restore_direct_levels(void)
{
        /*
         * If cpr didn't call pm_save_direct_levels, (because stopping user
         * threads failed) then we don't want to try to restore them
         */
        if (!pm_processes_stopped)
                return;

        ddi_walk_devs(ddi_root_node(), pm_restore_direct_lvl_walk, 0);
        pm_processes_stopped = 0;
}

static int
pm_restore_direct_lvl_walk(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))
        PMD_FUNC(pmf, "restore_direct_lvl_walk")
        int i, nc, result;
        int *ip;

        pm_info_t *info = PM_GET_PM_INFO(dip);
        if (!info)
                return (DDI_WALK_CONTINUE);

        if (PM_ISDIRECT(dip) && !PM_ISBC(dip)) {
                if ((nc = PM_NUMCMPTS(dip)) > 2) {
                        ip = &info->pmi_lp[nc - 1];
                } else {
                        ip = &info->pmi_levels[nc - 1];
                }
                /*
                 * Because fb drivers fail attempts to turn off the
                 * fb when the monitor is on, but treat a request to
                 * turn on the monitor as a request to turn on the
                 * fb too, we process components in descending order
                 * Because autopm is disabled and processes aren't
                 * running, it is ok to examine current power outside
                 * of the power lock
                 */
                for (i = nc - 1; i >= 0; i--, ip--) {
                        if (PM_CURPOWER(dip, i) == *ip)
                                continue;
                        if (pm_set_power(dip, i, *ip, PM_LEVEL_EXACT,
                            PM_CANBLOCK_BYPASS, 0, &result) != DDI_SUCCESS) {
                                cmn_err(CE_WARN, "cpr: unable "
                                    "to restore power level of "
                                    "component %d of directly "
                                    "power manged device %s@%s"
                                    " to %d",
                                    i, PM_NAME(dip),
                                    PM_ADDR(dip), *ip);
                                PMD(PMD_FAIL, ("%s: failed to restore "
                                    "%s@%s(%s#%d)[%d] exact(%d)->%d, "
                                    "errno %d\n", pmf, PM_DEVICE(dip), i,
                                    PM_CURPOWER(dip, i), *ip, result))
                        }
                }
                if (nc > 2) {
                        kmem_free(info->pmi_lp, nc * sizeof (int));
                        info->pmi_lp = NULL;
                }
        }
        return (DDI_WALK_CONTINUE);
}

/*
 * Stolen from the bootdev module
 * attempt to convert a path to a major number
 */
static major_t
i_path_to_major(char *path, char *leaf_name)
{
        extern major_t path_to_major(char *pathname);
        major_t maj;

        if ((maj = path_to_major(path)) == DDI_MAJOR_T_NONE) {
                maj = ddi_name_to_major(leaf_name);
        }

        return (maj);
}

static void i_pm_driver_removed(major_t major);

/*
 * When user calls rem_drv, we need to forget no-involuntary-power-cycles state
 * An entry in the list means that the device is detached, so we need to
 * adjust its ancestors as if they had just seen this attach, and any detached
 * ancestors need to have their list entries adjusted.
 */
void
pm_driver_removed(major_t major)
{

        /*
         * Serialize removal of drivers. This is to keep ancestors of
         * a node that is being deleted from getting deleted and added back
         * with different counters.
         */
        mutex_enter(&pm_remdrv_lock);
        i_pm_driver_removed(major);
        mutex_exit(&pm_remdrv_lock);
}

static void adjust_ancestors(char *, int);
static int pm_is_noinvol_ancestor(pm_noinvol_t *);
static void pm_noinvol_process_ancestors(char *);

/*
 * This routine is called recursively by pm_noinvol_process_ancestors()
 */
static void
i_pm_driver_removed(major_t major)
{
        PMD_FUNC(pmf, "driver_removed")
        pm_noinvol_t *ip, *pp = NULL;
        int wasvolpmd;
        ASSERT(major != DDI_MAJOR_T_NONE);
        PMD(PMD_NOINVOL, ("%s: %s\n", pmf, ddi_major_to_name(major)))
again:
        rw_enter(&pm_noinvol_rwlock, RW_WRITER);
        for (ip = pm_noinvol_head; ip; pp = ip, ip = ip->ni_next) {
                if (major != ip->ni_major)
                        continue;
                /*
                 * If it is an ancestor of no-invol node, which is
                 * not removed, skip it. This is to cover the case of
                 * ancestor removed without removing its descendants.
                 */
                if (pm_is_noinvol_ancestor(ip)) {
                        ip->ni_flags |= PMC_DRIVER_REMOVED;
                        continue;
                }
                wasvolpmd = ip->ni_wasvolpmd;
                /*
                 * remove the entry from the list
                 */
                if (pp) {
                        PMD(PMD_NOINVOL, ("%s: freeing %s, prev is %s\n",
                            pmf, ip->ni_path, pp->ni_path))
                        pp->ni_next = ip->ni_next;
                } else {
                        PMD(PMD_NOINVOL, ("%s: free %s head\n", pmf,
                            ip->ni_path))
                        ASSERT(pm_noinvol_head == ip);
                        pm_noinvol_head = ip->ni_next;
                }
                rw_exit(&pm_noinvol_rwlock);
                adjust_ancestors(ip->ni_path, wasvolpmd);
                /*
                 * Had an ancestor been removed before this node, it would have
                 * been skipped. Adjust the no-invol counters for such skipped
                 * ancestors.
                 */
                pm_noinvol_process_ancestors(ip->ni_path);
                kmem_free(ip->ni_path, ip->ni_size);
                kmem_free(ip, sizeof (*ip));
                goto again;
        }
        rw_exit(&pm_noinvol_rwlock);
}

/*
 * returns 1, if *aip is a ancestor of a no-invol node
 *         0, otherwise
 */
static int
pm_is_noinvol_ancestor(pm_noinvol_t *aip)
{
        pm_noinvol_t *ip;

        ASSERT(strlen(aip->ni_path) != 0);
        for (ip = pm_noinvol_head; ip; ip = ip->ni_next) {
                if (ip == aip)
                        continue;
                /*
                 * To be an ancestor, the path must be an initial substring of
                 * the descendent, and end just before a '/' in the
                 * descendent's path.
                 */
                if ((strstr(ip->ni_path, aip->ni_path) == ip->ni_path) &&
                    (ip->ni_path[strlen(aip->ni_path)] == '/'))
                        return (1);
        }
        return (0);
}

/*
 * scan through the pm_noinvolpm list adjusting ancestors of the current
 * node;  Modifies string *path.
 */
static void
adjust_ancestors(char *path, int wasvolpmd)
{
        PMD_FUNC(pmf, "adjust_ancestors")
        char *cp;
        pm_noinvol_t *lp;
        pm_noinvol_t *pp = NULL;
        major_t locked = DDI_MAJOR_T_NONE;
        dev_info_t *dip;
        char    *pathbuf;
        size_t pathbuflen = strlen(path) + 1;

        /*
         * First we look up the ancestor's dip.  If we find it, then we
         * adjust counts up the tree
         */
        PMD(PMD_NOINVOL, ("%s: %s wasvolpmd %d\n", pmf, path, wasvolpmd))
        pathbuf = kmem_alloc(pathbuflen, KM_SLEEP);
        (void) strcpy(pathbuf, path);
        cp = strrchr(pathbuf, '/');
        if (cp == NULL) {
                /* if no ancestors, then nothing to do */
                kmem_free(pathbuf, pathbuflen);
                return;
        }
        *cp = '\0';
        dip = pm_name_to_dip(pathbuf, 1);
        if (dip != NULL) {
                locked = PM_MAJOR(dip);

                (void) pm_noinvol_update(PM_BP_NOINVOL_REMDRV, 0, wasvolpmd,
                    path, dip);

                if (locked != DDI_MAJOR_T_NONE)
                        ddi_release_devi(dip);
        } else {
                char *apath;
                size_t len = strlen(pathbuf) + 1;
                int  lock_held = 1;

                /*
                 * Now check for ancestors that exist only in the list
                 */
                apath = kmem_alloc(len, KM_SLEEP);
                (void) strcpy(apath, pathbuf);
                rw_enter(&pm_noinvol_rwlock, RW_WRITER);
                for (lp = pm_noinvol_head; lp; pp = lp, lp = lp->ni_next) {
                        /*
                         * This can only happen once.  Since we have to drop
                         * the lock, we need to extract the relevant info.
                         */
                        if (strcmp(pathbuf, lp->ni_path) == 0) {
                                PMD(PMD_NOINVOL, ("%s: %s no %d -> %d\n", pmf,
                                    lp->ni_path, lp->ni_noinvolpm,
                                    lp->ni_noinvolpm - 1))
                                lp->ni_noinvolpm--;
                                if (wasvolpmd && lp->ni_volpmd) {
                                        PMD(PMD_NOINVOL, ("%s: %s vol %d -> "
                                            "%d\n", pmf, lp->ni_path,
                                            lp->ni_volpmd, lp->ni_volpmd - 1))
                                        lp->ni_volpmd--;
                                }
                                /*
                                 * remove the entry from the list, if there
                                 * are no more no-invol descendants and node
                                 * itself is not a no-invol node.
                                 */
                                if (!(lp->ni_noinvolpm ||
                                    (lp->ni_flags & PMC_NO_INVOL))) {
                                        ASSERT(lp->ni_volpmd == 0);
                                        if (pp) {
                                                PMD(PMD_NOINVOL, ("%s: freeing "
                                                    "%s, prev is %s\n", pmf,
                                                    lp->ni_path, pp->ni_path))
                                                pp->ni_next = lp->ni_next;
                                        } else {
                                                PMD(PMD_NOINVOL, ("%s: free %s "
                                                    "head\n", pmf, lp->ni_path))
                                                ASSERT(pm_noinvol_head == lp);
                                                pm_noinvol_head = lp->ni_next;
                                        }
                                        lock_held = 0;
                                        rw_exit(&pm_noinvol_rwlock);
                                        adjust_ancestors(apath, wasvolpmd);
                                        /* restore apath */
                                        (void) strcpy(apath, pathbuf);
                                        kmem_free(lp->ni_path, lp->ni_size);
                                        kmem_free(lp, sizeof (*lp));
                                }
                                break;
                        }
                }
                if (lock_held)
                        rw_exit(&pm_noinvol_rwlock);
                adjust_ancestors(apath, wasvolpmd);
                kmem_free(apath, len);
        }
        kmem_free(pathbuf, pathbuflen);
}

/*
 * Do no-invol processing for any ancestors i.e. adjust counters of ancestors,
 * which were skipped even though their drivers were removed.
 */
static void
pm_noinvol_process_ancestors(char *path)
{
        pm_noinvol_t *lp;

        rw_enter(&pm_noinvol_rwlock, RW_READER);
        for (lp = pm_noinvol_head; lp; lp = lp->ni_next) {
                if (strstr(path, lp->ni_path) &&
                    (lp->ni_flags & PMC_DRIVER_REMOVED)) {
                        rw_exit(&pm_noinvol_rwlock);
                        i_pm_driver_removed(lp->ni_major);
                        return;
                }
        }
        rw_exit(&pm_noinvol_rwlock);
}

/*
 * Returns true if (detached) device needs to be kept up because it exported the
 * "no-involuntary-power-cycles" property or we're pretending it did (console
 * fb case) or it is an ancestor of such a device and has used up the "one
 * free cycle" allowed when all such leaf nodes have voluntarily powered down
 * upon detach.  In any event, we need an exact hit on the path or we return
 * false.
 */
int
pm_noinvol_detached(char *path)
{
        PMD_FUNC(pmf, "noinvol_detached")
        pm_noinvol_t *ip;
        int ret = 0;

        rw_enter(&pm_noinvol_rwlock, RW_READER);
        for (ip = pm_noinvol_head; ip; ip = ip->ni_next) {
                if (strcmp(path, ip->ni_path) == 0) {
                        if (ip->ni_flags & PMC_CONSOLE_FB) {
                                PMD(PMD_NOINVOL | PMD_CFB, ("%s: inhibits CFB "
                                    "%s\n", pmf, path))
                                ret = 1;
                                break;
                        }
#ifdef  DEBUG
                        if (ip->ni_noinvolpm != ip->ni_volpmd)
                                PMD(PMD_NOINVOL, ("%s: (%d != %d) inhibits %s"
                                    "\n", pmf, ip->ni_noinvolpm, ip->ni_volpmd,
                                    path))
#endif
                        ret = (ip->ni_noinvolpm != ip->ni_volpmd);
                        break;
                }
        }
        rw_exit(&pm_noinvol_rwlock);
        return (ret);
}

int
pm_is_cfb(dev_info_t *dip)
{
        return (dip == cfb_dip);
}

#ifdef  DEBUG
/*
 * Return true if all components of the console frame buffer are at
 * "normal" power, i.e., fully on.  For the case where the console is not
 * a framebuffer, we also return true
 */
int
pm_cfb_is_up(void)
{
        return (pm_cfb_comps_off == 0);
}
#endif

/*
 * Preventing scan from powering down the node by incrementing the
 * kidsupcnt.
 */
void
pm_hold_power(dev_info_t *dip)
{
        e_pm_hold_rele_power(dip, 1);
}

/*
 * Releasing the hold by decrementing the kidsupcnt allowing scan
 * to power down the node if all conditions are met.
 */
void
pm_rele_power(dev_info_t *dip)
{
        e_pm_hold_rele_power(dip, -1);
}

/*
 * A wrapper of pm_all_to_normal() to power up a dip
 * to its normal level
 */
int
pm_powerup(dev_info_t *dip)
{
        PMD_FUNC(pmf, "pm_powerup")

        PMD(PMD_ALLNORM, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        ASSERT(!(servicing_interrupt()));

        /*
         * in case this node is not already participating pm
         */
        if (!PM_GET_PM_INFO(dip)) {
                if (!DEVI_IS_ATTACHING(dip))
                        return (DDI_SUCCESS);
                if (pm_start(dip) != DDI_SUCCESS)
                        return (DDI_FAILURE);
                if (!PM_GET_PM_INFO(dip))
                        return (DDI_SUCCESS);
        }

        return (pm_all_to_normal(dip, PM_CANBLOCK_BLOCK));
}

int
pm_rescan_walk(dev_info_t *dip, void *arg)
{
        _NOTE(ARGUNUSED(arg))

        if (!PM_GET_PM_INFO(dip) || PM_ISBC(dip))
                return (DDI_WALK_CONTINUE);

        /*
         * Currently pm_cpr_callb/resume code is the only caller
         * and it needs to make sure that stopped scan get
         * reactivated. Otherwise, rescan walk needn't reactive
         * stopped scan.
         */
        pm_scan_init(dip);

        (void) pm_rescan(dip);
        return (DDI_WALK_CONTINUE);
}

static dev_info_t *
pm_get_next_descendent(dev_info_t *dip, dev_info_t *tdip)
{
        dev_info_t *wdip, *pdip;

        for (wdip = tdip; wdip != dip; wdip = pdip) {
                pdip = ddi_get_parent(wdip);
                if (pdip == dip)
                        return (wdip);
        }
        return (NULL);
}

int
pm_busop_bus_power(dev_info_t *dip, void *impl_arg, pm_bus_power_op_t op,
    void *arg, void *result)
{
        PMD_FUNC(pmf, "bp_bus_power")
        dev_info_t      *cdip;
        pm_info_t       *cinfo;
        pm_bp_child_pwrchg_t    *bpc;
        pm_sp_misc_t            *pspm;
        pm_bp_nexus_pwrup_t *bpn;
        pm_bp_child_pwrchg_t new_bpc;
        pm_bp_noinvol_t *bpi;
        dev_info_t *tdip;
        char *pathbuf;
        int             ret = DDI_SUCCESS;
        int             errno = 0;
        pm_component_t *cp;

        PMD(PMD_SET, ("%s: %s@%s(%s#%d) %s\n", pmf, PM_DEVICE(dip),
            pm_decode_op(op)))
        switch (op) {
        case BUS_POWER_CHILD_PWRCHG:
                bpc = (pm_bp_child_pwrchg_t *)arg;
                pspm = (pm_sp_misc_t *)bpc->bpc_private;
                tdip = bpc->bpc_dip;
                cdip = pm_get_next_descendent(dip, tdip);
                cinfo = PM_GET_PM_INFO(cdip);
                if (cdip != tdip) {
                        /*
                         * If the node is an involved parent, it needs to
                         * power up the node as it is needed.  There is nothing
                         * else the framework can do here.
                         */
                        if (PM_WANTS_NOTIFICATION(cdip)) {
                                PMD(PMD_SET, ("%s: call bus_power for "
                                    "%s@%s(%s#%d)\n", pmf, PM_DEVICE(cdip)))
                                return ((*PM_BUS_POWER_FUNC(cdip))(cdip,
                                    impl_arg, op, arg, result));
                        }
                        ASSERT(pspm->pspm_direction == PM_LEVEL_UPONLY ||
                            pspm->pspm_direction == PM_LEVEL_DOWNONLY ||
                            pspm->pspm_direction == PM_LEVEL_EXACT);
                        /*
                         * we presume that the parent needs to be up in
                         * order for the child to change state (either
                         * because it must already be on if the child is on
                         * (and the pm_all_to_normal_nexus() will be a nop)
                         * or because it will need to be on for the child
                         * to come on; so we make the call regardless
                         */
                        pm_hold_power(cdip);
                        if (cinfo) {
                                pm_canblock_t canblock = pspm->pspm_canblock;
                                ret = pm_all_to_normal_nexus(cdip, canblock);
                                if (ret != DDI_SUCCESS) {
                                        pm_rele_power(cdip);
                                        return (ret);
                                }
                        }
                        PMD(PMD_SET, ("%s: walk down to %s@%s(%s#%d)\n", pmf,
                            PM_DEVICE(cdip)))
                        ret = pm_busop_bus_power(cdip, impl_arg, op, arg,
                            result);
                        pm_rele_power(cdip);
                } else {
                        ret = pm_busop_set_power(cdip, impl_arg, op, arg,
                            result);
                }
                return (ret);

        case BUS_POWER_NEXUS_PWRUP:
                bpn = (pm_bp_nexus_pwrup_t *)arg;
                pspm = (pm_sp_misc_t *)bpn->bpn_private;

                if (!e_pm_valid_info(dip, NULL) ||
                    !e_pm_valid_comp(dip, bpn->bpn_comp, &cp) ||
                    !e_pm_valid_power(dip, bpn->bpn_comp, bpn->bpn_level)) {
                        PMD(PMD_SET, ("%s: %s@%s(%s#%d) has no pm info; EIO\n",
                            pmf, PM_DEVICE(dip)))
                        *pspm->pspm_errnop = EIO;
                        *(int *)result = DDI_FAILURE;
                        return (DDI_FAILURE);
                }

                ASSERT(bpn->bpn_dip == dip);
                PMD(PMD_SET, ("%s: nexus powerup for %s@%s(%s#%d)\n", pmf,
                    PM_DEVICE(dip)))
                new_bpc.bpc_dip = dip;
                pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);
                new_bpc.bpc_path = ddi_pathname(dip, pathbuf);
                new_bpc.bpc_comp = bpn->bpn_comp;
                new_bpc.bpc_olevel = PM_CURPOWER(dip, bpn->bpn_comp);
                new_bpc.bpc_nlevel = bpn->bpn_level;
                new_bpc.bpc_private = bpn->bpn_private;
                ((pm_sp_misc_t *)(new_bpc.bpc_private))->pspm_direction =
                    PM_LEVEL_UPONLY;
                ((pm_sp_misc_t *)(new_bpc.bpc_private))->pspm_errnop =
                    &errno;
                ret = pm_busop_set_power(dip, impl_arg, BUS_POWER_CHILD_PWRCHG,
                    (void *)&new_bpc, result);
                kmem_free(pathbuf, MAXPATHLEN);
                return (ret);

        case BUS_POWER_NOINVOL:
                bpi = (pm_bp_noinvol_t *)arg;
                tdip = bpi->bpni_dip;
                cdip = pm_get_next_descendent(dip, tdip);

                /* In case of rem_drv, the leaf node has been removed */
                if (cdip == NULL)
                        return (DDI_SUCCESS);

                cinfo = PM_GET_PM_INFO(cdip);
                if (cdip != tdip) {
                        if (PM_WANTS_NOTIFICATION(cdip)) {
                                PMD(PMD_NOINVOL,
                                    ("%s: call bus_power for %s@%s(%s#%d)\n",
                                    pmf, PM_DEVICE(cdip)))
                                ret = (*PM_BUS_POWER_FUNC(cdip))
                                    (cdip, NULL, op, arg, result);
                                if ((cinfo) && (ret == DDI_SUCCESS))
                                        (void) pm_noinvol_update_node(cdip,
                                            bpi);
                                return (ret);
                        } else {
                                PMD(PMD_NOINVOL,
                                    ("%s: walk down to %s@%s(%s#%d)\n", pmf,
                                    PM_DEVICE(cdip)))
                                ret = pm_busop_bus_power(cdip, NULL, op,
                                    arg, result);
                                /*
                                 * Update the current node.
                                 */
                                if ((cinfo) && (ret == DDI_SUCCESS))
                                        (void) pm_noinvol_update_node(cdip,
                                            bpi);
                                return (ret);
                        }
                } else {
                        /*
                         * For attach, detach, power up:
                         * Do nothing for leaf node since its
                         * counts are already updated.
                         * For CFB and driver removal, since the
                         * path and the target dip passed in is up to and incl.
                         * the immediate ancestor, need to do the update.
                         */
                        PMD(PMD_NOINVOL, ("%s: target %s@%s(%s#%d) is "
                            "reached\n", pmf, PM_DEVICE(cdip)))
                        if (cinfo && ((bpi->bpni_cmd == PM_BP_NOINVOL_REMDRV) ||
                            (bpi->bpni_cmd == PM_BP_NOINVOL_CFB)))
                                (void) pm_noinvol_update_node(cdip, bpi);
                        return (DDI_SUCCESS);
                }

        default:
                PMD(PMD_SET, ("%s: operation %d is not supported!\n", pmf, op))
                return (DDI_FAILURE);
        }
}

static int
pm_busop_set_power(dev_info_t *dip, void *impl_arg, pm_bus_power_op_t op,
    void *arg, void *resultp)
{
        _NOTE(ARGUNUSED(impl_arg))
        PMD_FUNC(pmf, "bp_set_power")
        pm_ppm_devlist_t *devl = NULL;
        int clevel, circ;
#ifdef  DEBUG
        int circ_db, ccirc_db;
#endif
        int ret = DDI_SUCCESS;
        dev_info_t *cdip;
        pm_bp_child_pwrchg_t *bpc = (pm_bp_child_pwrchg_t *)arg;
        pm_sp_misc_t *pspm = (pm_sp_misc_t *)bpc->bpc_private;
        pm_canblock_t canblock = pspm->pspm_canblock;
        int scan = pspm->pspm_scan;
        int comp = bpc->bpc_comp;
        int olevel = bpc->bpc_olevel;
        int nlevel = bpc->bpc_nlevel;
        int comps_off_incr = 0;
        dev_info_t *pdip = ddi_get_parent(dip);
        int dodeps;
        int direction = pspm->pspm_direction;
        int *errnop = pspm->pspm_errnop;
#ifdef PMDDEBUG
        char *dir = pm_decode_direction(direction);
#endif
        int *iresp = (int *)resultp;
        time_t  idletime, thresh;
        pm_component_t *cp = PM_CP(dip, comp);
        int work_type;

        *iresp = DDI_SUCCESS;
        *errnop = 0;
        ASSERT(op == BUS_POWER_CHILD_PWRCHG);
        PMD(PMD_SET, ("%s: %s@%s(%s#%d) %s\n", pmf, PM_DEVICE(dip),
            pm_decode_op(op)))

        /*
         * The following set of conditions indicate we are here to handle a
         * driver's pm_[raise|lower]_power request, but the device is being
         * power managed (PM_DIRECT_PM) by a user process.  For that case
         * we want to pm_block and pass a status back to the caller based
         * on whether the controlling process's next activity on the device
         * matches the current request or not.  This distinction tells
         * downstream functions to avoid calling into a driver or changing
         * the framework's power state.  To actually block, we need:
         *
         * PM_ISDIRECT(dip)
         *      no reason to block unless a process is directly controlling dev
         * direction != PM_LEVEL_EXACT
         *      EXACT is used by controlling proc's PM_SET_CURRENT_POWER ioctl
         * !pm_processes_stopped
         *      don't block if controlling proc already be stopped for cpr
         * canblock != PM_CANBLOCK_BYPASS
         *      our caller must not have explicitly prevented blocking
         */
        if (direction != PM_LEVEL_EXACT && canblock != PM_CANBLOCK_BYPASS) {
                PM_LOCK_DIP(dip);
                while (PM_ISDIRECT(dip) && !pm_processes_stopped) {
                        /* releases dip lock */
                        ret = pm_busop_match_request(dip, bpc);
                        if (ret == EAGAIN) {
                                PM_LOCK_DIP(dip);
                                continue;
                        }
                        return (*iresp = ret);
                }
                PM_UNLOCK_DIP(dip);
        }
        /* BC device is never scanned, so power will stick until we are done */
        if (PM_ISBC(dip) && comp != 0 && nlevel != 0 &&
            direction != PM_LEVEL_DOWNONLY) {
                int nrmpwr0 = pm_get_normal_power(dip, 0);
                if (pm_set_power(dip, 0, nrmpwr0, direction,
                    canblock, 0, resultp) != DDI_SUCCESS) {
                        /* *resultp set by pm_set_power */
                        return (DDI_FAILURE);
                }
        }
        if (PM_WANTS_NOTIFICATION(pdip)) {
                PMD(PMD_SET, ("%s: pre_notify %s@%s(%s#%d) for child "
                    "%s@%s(%s#%d)\n", pmf, PM_DEVICE(pdip), PM_DEVICE(dip)))
                ret = (*PM_BUS_POWER_FUNC(pdip))(pdip, NULL,
                    BUS_POWER_PRE_NOTIFICATION, bpc, resultp);
                if (ret != DDI_SUCCESS) {
                        PMD(PMD_SET, ("%s: failed to pre_notify %s@%s(%s#%d)\n",
                            pmf, PM_DEVICE(pdip)))
                        return (DDI_FAILURE);
                }
        } else {
                /*
                 * Since we don't know what the actual power level is,
                 * we place a power hold on the parent no matter what
                 * component and level is changing.
                 */
                pm_hold_power(pdip);
        }
        PM_LOCK_POWER(dip, &circ);
        clevel = PM_CURPOWER(dip, comp);
        /*
         * It's possible that a call was made to pm_update_maxpower()
         * on another thread before we took the lock above. So, we need to
         * make sure that this request isn't processed after the
         * change of power executed on behalf of pm_update_maxpower().
         */
        if (nlevel > pm_get_normal_power(dip, comp)) {
                PMD(PMD_SET, ("%s: requested level is higher than normal.\n",
                    pmf))
                ret = DDI_FAILURE;
                *iresp = DDI_FAILURE;
                goto post_notify;
        }
        PMD(PMD_SET, ("%s: %s@%s(%s#%d), cmp=%d, olvl=%d, nlvl=%d, clvl=%d, "
            "dir=%s\n", pmf, PM_DEVICE(dip), comp, bpc->bpc_olevel, nlevel,
            clevel, dir))
        switch (direction) {
        case PM_LEVEL_UPONLY:
                /* Powering up */
                if (clevel >= nlevel) {
                        PMD(PMD_SET, ("%s: current level is already "
                            "at or above the requested level.\n", pmf))
                        *iresp = DDI_SUCCESS;
                        ret = DDI_SUCCESS;
                        goto post_notify;
                }
                break;
        case PM_LEVEL_EXACT:
                /* specific level request */
                if (clevel == nlevel && !PM_ISBC(dip)) {
                        PMD(PMD_SET, ("%s: current level is already "
                            "at the requested level.\n", pmf))
                        *iresp = DDI_SUCCESS;
                        ret = DDI_SUCCESS;
                        goto post_notify;
                } else if (PM_IS_CFB(dip) && (nlevel < clevel)) {
                        PMD(PMD_CFB, ("%s: powerdown of console\n", pmf))
                        if (!pm_cfb_enabled) {
                                PMD(PMD_ERROR | PMD_CFB,
                                    ("%s: !pm_cfb_enabled, fails\n", pmf))
                                *errnop = EINVAL;
                                *iresp = DDI_FAILURE;
                                ret = DDI_FAILURE;
                                goto post_notify;
                        }
                        mutex_enter(&pm_cfb_lock);
                        while (cfb_inuse) {
                                mutex_exit(&pm_cfb_lock);
                                if (delay_sig(1) == EINTR) {
                                        ret = DDI_FAILURE;
                                        *iresp = DDI_FAILURE;
                                        *errnop = EINTR;
                                        goto post_notify;
                                }
                                mutex_enter(&pm_cfb_lock);
                        }
                        mutex_exit(&pm_cfb_lock);
                }
                break;
        case PM_LEVEL_DOWNONLY:
                /* Powering down */
                thresh = cur_threshold(dip, comp);
                idletime = gethrestime_sec() - cp->pmc_timestamp;
                if (scan && ((PM_KUC(dip) != 0) ||
                    (cp->pmc_busycount > 0) ||
                    ((idletime < thresh) && !PM_IS_PID(dip)))) {
#ifdef  DEBUG
                        if (DEVI(dip)->devi_pm_kidsupcnt != 0)
                                PMD(PMD_SET, ("%s: scan failed: "
                                    "kidsupcnt != 0\n", pmf))
                        if (cp->pmc_busycount > 0)
                                PMD(PMD_SET, ("%s: scan failed: "
                                    "device become busy\n", pmf))
                        if (idletime < thresh)
                                PMD(PMD_SET, ("%s: scan failed: device "
                                    "hasn't been idle long enough\n", pmf))
#endif
                        *iresp = DDI_FAILURE;
                        *errnop = EBUSY;
                        ret = DDI_FAILURE;
                        goto post_notify;
                } else if (clevel != PM_LEVEL_UNKNOWN && clevel <= nlevel) {
                        PMD(PMD_SET, ("%s: current level is already at "
                            "or below the requested level.\n", pmf))
                        *iresp = DDI_SUCCESS;
                        ret = DDI_SUCCESS;
                        goto post_notify;
                }
                break;
        }

        if (PM_IS_CFB(dip) && (comps_off_incr =
            calc_cfb_comps_incr(dip, comp, clevel, nlevel)) > 0) {
                /*
                 * Pre-adjust pm_cfb_comps_off if lowering a console fb
                 * component from full power.  Remember that we tried to
                 * lower power in case it fails and we need to back out
                 * the adjustment.
                 */
                update_comps_off(comps_off_incr, dip);
                PMD(PMD_CFB, ("%s: %s@%s(%s#%d)[%d] %d->%d cfb_comps_off->%d\n",
                    pmf, PM_DEVICE(dip), comp, clevel, nlevel,
                    pm_cfb_comps_off))
        }

        if ((*iresp = power_dev(dip,
            comp, nlevel, clevel, canblock, &devl)) == DDI_SUCCESS) {
#ifdef DEBUG
                /*
                 * All descendents of this node should already be powered off.
                 */
                if (PM_CURPOWER(dip, comp) == 0) {
                        pm_desc_pwrchk_t pdpchk;
                        pdpchk.pdpc_dip = dip;
                        pdpchk.pdpc_par_involved = PM_WANTS_NOTIFICATION(dip);
                        ndi_devi_enter(dip, &circ_db);
                        for (cdip = ddi_get_child(dip); cdip != NULL;
                            cdip = ddi_get_next_sibling(cdip)) {
                                ndi_devi_enter(cdip, &ccirc_db);
                                ddi_walk_devs(cdip, pm_desc_pwrchk_walk,
                                    (void *)&pdpchk);
                                ndi_devi_exit(cdip, ccirc_db);
                        }
                        ndi_devi_exit(dip, circ_db);
                }
#endif
                /*
                 * Post-adjust pm_cfb_comps_off if we brought an fb component
                 * back up to full power.
                 */
                if (PM_IS_CFB(dip) && comps_off_incr < 0) {
                        update_comps_off(comps_off_incr, dip);
                        PMD(PMD_CFB, ("%s: %s@%s(%s#%d)[%d] %d->%d "
                            "cfb_comps_off->%d\n", pmf, PM_DEVICE(dip),
                            comp, clevel, nlevel, pm_cfb_comps_off))
                }
                dodeps = 0;
                if (POWERING_OFF(clevel, nlevel)) {
                        if (PM_ISBC(dip)) {
                                dodeps = (comp == 0);
                        } else {
                                int i;
                                dodeps = 1;
                                for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                                        /* if some component still on */
                                        if (PM_CURPOWER(dip, i)) {
                                                dodeps = 0;
                                                break;
                                        }
                                }
                        }
                        if (dodeps)
                                work_type = PM_DEP_WK_POWER_OFF;
                } else if (POWERING_ON(clevel, nlevel)) {
                        if (PM_ISBC(dip)) {
                                dodeps = (comp == 0);
                        } else {
                                int i;
                                dodeps = 1;
                                for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                                        if (i == comp)
                                                continue;
                                        if (PM_CURPOWER(dip, i) > 0) {
                                                dodeps = 0;
                                                break;
                                        }
                                }
                        }
                        if (dodeps)
                                work_type = PM_DEP_WK_POWER_ON;
                }

                if (dodeps) {
                        char *pathbuf = kmem_alloc(MAXPATHLEN, KM_SLEEP);

                        (void) ddi_pathname(dip, pathbuf);
                        pm_dispatch_to_dep_thread(work_type, pathbuf, NULL,
                            PM_DEP_NOWAIT, NULL, 0);
                        kmem_free(pathbuf, MAXPATHLEN);
                }
                if ((PM_CURPOWER(dip, comp) == nlevel) && pm_watchers()) {
                        int old;

                        /* If old power cached during deadlock, use it. */
                        old = (cp->pmc_flags & PM_PHC_WHILE_SET_POWER ?
                            cp->pmc_phc_pwr : olevel);
                        mutex_enter(&pm_rsvp_lock);
                        pm_enqueue_notify(PSC_HAS_CHANGED, dip, comp, nlevel,
                            old, canblock);
                        pm_enqueue_notify_others(&devl, canblock);
                        mutex_exit(&pm_rsvp_lock);
                } else {
                        pm_ppm_devlist_t *p;
                        pm_ppm_devlist_t *next;
                        for (p = devl; p != NULL; p = next) {
                                next = p->ppd_next;
                                kmem_free(p, sizeof (pm_ppm_devlist_t));
                        }
                        devl = NULL;
                }

                /*
                 * If we are coming from a scan, don't do it again,
                 * else we can have infinite loops.
                 */
                if (!scan)
                        pm_rescan(dip);
        } else {
                /* if we incremented pm_comps_off_count, but failed */
                if (comps_off_incr > 0) {
                        update_comps_off(-comps_off_incr, dip);
                        PMD(PMD_CFB, ("%s: %s@%s(%s#%d)[%d] %d->%d "
                            "cfb_comps_off->%d\n", pmf, PM_DEVICE(dip),
                            comp, clevel, nlevel, pm_cfb_comps_off))
                }
                *errnop = EIO;
        }

post_notify:
        /*
         * This thread may have been in deadlock with pm_power_has_changed.
         * Before releasing power lock, clear the flag which marks this
         * condition.
         */
        cp->pmc_flags &= ~PM_PHC_WHILE_SET_POWER;

        /*
         * Update the old power level in the bus power structure with the
         * actual power level before the transition was made to the new level.
         * Some involved parents depend on this information to keep track of
         * their children's power transition.
         */
        if (*iresp != DDI_FAILURE)
                bpc->bpc_olevel = clevel;

        if (PM_WANTS_NOTIFICATION(pdip)) {
                ret = (*PM_BUS_POWER_FUNC(pdip))(pdip, NULL,
                    BUS_POWER_POST_NOTIFICATION, bpc, resultp);
                PM_UNLOCK_POWER(dip, circ);
                PMD(PMD_SET, ("%s: post_notify %s@%s(%s#%d) for "
                    "child %s@%s(%s#%d), ret=%d\n", pmf, PM_DEVICE(pdip),
                    PM_DEVICE(dip), ret))
        } else {
                nlevel = cur_power(cp); /* in case phc deadlock updated pwr */
                PM_UNLOCK_POWER(dip, circ);
                /*
                 * Now that we know what power transition has occurred
                 * (if any), release the power hold.  Leave the hold
                 * in effect in the case of OFF->ON transition.
                 */
                if (!(clevel == 0 && nlevel > 0 &&
                    (!PM_ISBC(dip) || comp == 0)))
                        pm_rele_power(pdip);
                /*
                 * If the power transition was an ON->OFF transition,
                 * remove the power hold from the parent.
                 */
                if ((clevel > 0 || clevel == PM_LEVEL_UNKNOWN) &&
                    nlevel == 0 && (!PM_ISBC(dip) || comp == 0))
                        pm_rele_power(pdip);
        }
        if (*iresp != DDI_SUCCESS || ret != DDI_SUCCESS)
                return (DDI_FAILURE);
        else
                return (DDI_SUCCESS);
}

/*
 * If an app (SunVTS or Xsun) has taken control, then block until it
 * gives it up or makes the requested power level change, unless
 * we have other instructions about blocking.  Returns DDI_SUCCESS,
 * DDI_FAILURE or EAGAIN (owner released device from directpm).
 */
static int
pm_busop_match_request(dev_info_t *dip, void *arg)
{
        PMD_FUNC(pmf, "bp_match_request")
        pm_bp_child_pwrchg_t *bpc = (pm_bp_child_pwrchg_t *)arg;
        pm_sp_misc_t *pspm = (pm_sp_misc_t *)bpc->bpc_private;
        int comp = bpc->bpc_comp;
        int nlevel = bpc->bpc_nlevel;
        pm_canblock_t canblock = pspm->pspm_canblock;
        int direction = pspm->pspm_direction;
        int clevel, circ;

        ASSERT(PM_IAM_LOCKING_DIP(dip));
        PM_LOCK_POWER(dip, &circ);
        clevel = PM_CURPOWER(dip, comp);
        PMD(PMD_SET, ("%s: %s@%s(%s#%d), cmp=%d, nlvl=%d, clvl=%d\n",
            pmf, PM_DEVICE(dip), comp, nlevel, clevel))
        if (direction == PM_LEVEL_UPONLY) {
                if (clevel >= nlevel) {
                        PM_UNLOCK_POWER(dip, circ);
                        PM_UNLOCK_DIP(dip);
                        return (DDI_SUCCESS);
                }
        } else if (clevel == nlevel) {
                PM_UNLOCK_POWER(dip, circ);
                PM_UNLOCK_DIP(dip);
                return (DDI_SUCCESS);
        }
        if (canblock == PM_CANBLOCK_FAIL) {
                PM_UNLOCK_POWER(dip, circ);
                PM_UNLOCK_DIP(dip);
                return (DDI_FAILURE);
        }
        if (canblock == PM_CANBLOCK_BLOCK) {
                /*
                 * To avoid a deadlock, we must not hold the
                 * power lock when we pm_block.
                 */
                PM_UNLOCK_POWER(dip, circ);
                PMD(PMD_SET, ("%s: blocking\n", pmf))
                /* pm_block releases dip lock */
                switch (pm_block(dip, comp, nlevel, clevel)) {
                case PMP_RELEASE:
                        return (EAGAIN);
                case PMP_SUCCEED:
                        return (DDI_SUCCESS);
                case PMP_FAIL:
                        return (DDI_FAILURE);
                }
        } else {
                ASSERT(0);
        }
        _NOTE(NOTREACHED);
        return (DDI_FAILURE);   /* keep gcc happy */
}

static int
pm_all_to_normal_nexus(dev_info_t *dip, pm_canblock_t canblock)
{
        PMD_FUNC(pmf, "all_to_normal_nexus")
        int             *normal;
        int             i, ncomps;
        size_t          size;
        int             changefailed = 0;
        int             ret, result = DDI_SUCCESS;
        pm_bp_nexus_pwrup_t     bpn;
        pm_sp_misc_t    pspm;

        ASSERT(PM_GET_PM_INFO(dip));
        PMD(PMD_ALLNORM, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        if (pm_get_norm_pwrs(dip, &normal, &size) != DDI_SUCCESS) {
                PMD(PMD_ALLNORM, ("%s: can't get norm pwrs\n", pmf))
                return (DDI_FAILURE);
        }
        ncomps = PM_NUMCMPTS(dip);
        for (i = 0; i < ncomps; i++) {
                bpn.bpn_dip = dip;
                bpn.bpn_comp = i;
                bpn.bpn_level = normal[i];
                pspm.pspm_canblock = canblock;
                pspm.pspm_scan = 0;
                bpn.bpn_private = &pspm;
                ret = pm_busop_bus_power(dip, NULL, BUS_POWER_NEXUS_PWRUP,
                    (void *)&bpn, (void *)&result);
                if (ret != DDI_SUCCESS || result != DDI_SUCCESS) {
                        PMD(PMD_FAIL | PMD_ALLNORM, ("%s: %s@%s(%s#%d)[%d] "
                            "->%d failure result %d\n", pmf, PM_DEVICE(dip),
                            i, normal[i], result))
                        changefailed++;
                }
        }
        kmem_free(normal, size);
        if (changefailed) {
                PMD(PMD_FAIL, ("%s: failed to set %d comps %s@%s(%s#%d) "
                    "full power\n", pmf, changefailed, PM_DEVICE(dip)))
                return (DDI_FAILURE);
        }
        return (DDI_SUCCESS);
}

int
pm_noinvol_update(int subcmd, int volpmd, int wasvolpmd, char *path,
    dev_info_t *tdip)
{
        PMD_FUNC(pmf, "noinvol_update")
        pm_bp_noinvol_t args;
        int ret;
        int result = DDI_SUCCESS;

        args.bpni_path = path;
        args.bpni_dip = tdip;
        args.bpni_cmd = subcmd;
        args.bpni_wasvolpmd = wasvolpmd;
        args.bpni_volpmd = volpmd;
        PMD(PMD_NOINVOL, ("%s: update for path %s tdip %p subcmd %d "
            "volpmd %d wasvolpmd %d\n", pmf,
            path, (void *)tdip, subcmd, wasvolpmd, volpmd))
        ret = pm_busop_bus_power(ddi_root_node(), NULL, BUS_POWER_NOINVOL,
            &args, &result);
        return (ret);
}

void
pm_noinvol_update_node(dev_info_t *dip, pm_bp_noinvol_t *req)
{
        PMD_FUNC(pmf, "noinvol_update_node")

        PMD(PMD_NOINVOL, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        switch (req->bpni_cmd) {
        case PM_BP_NOINVOL_ATTACH:
                PMD(PMD_NOINVOL, ("%s: PM_PB_NOINVOL_ATTACH %s@%s(%s#%d) "
                    "noinvol %d->%d\n", pmf, PM_DEVICE(dip),
                    DEVI(dip)->devi_pm_noinvolpm,
                    DEVI(dip)->devi_pm_noinvolpm - 1))
                ASSERT(DEVI(dip)->devi_pm_noinvolpm);
                PM_LOCK_DIP(dip);
                DEVI(dip)->devi_pm_noinvolpm--;
                if (req->bpni_wasvolpmd) {
                        PMD(PMD_NOINVOL, ("%s: PM_BP_NOINVOL_ATTACH "
                            "%s@%s(%s#%d) volpmd %d->%d\n", pmf,
                            PM_DEVICE(dip), DEVI(dip)->devi_pm_volpmd,
                            DEVI(dip)->devi_pm_volpmd - 1))
                        if (DEVI(dip)->devi_pm_volpmd)
                                DEVI(dip)->devi_pm_volpmd--;
                }
                PM_UNLOCK_DIP(dip);
                break;

        case PM_BP_NOINVOL_DETACH:
                PMD(PMD_NOINVOL, ("%s: PM_BP_NOINVOL_DETACH %s@%s(%s#%d) "
                    "noinvolpm %d->%d\n", pmf, PM_DEVICE(dip),
                    DEVI(dip)->devi_pm_noinvolpm,
                    DEVI(dip)->devi_pm_noinvolpm + 1))
                PM_LOCK_DIP(dip);
                DEVI(dip)->devi_pm_noinvolpm++;
                if (req->bpni_wasvolpmd) {
                        PMD(PMD_NOINVOL, ("%s: PM_BP_NOINVOL_DETACH "
                            "%s@%s(%s#%d) volpmd %d->%d\n", pmf,
                            PM_DEVICE(dip), DEVI(dip)->devi_pm_volpmd,
                            DEVI(dip)->devi_pm_volpmd + 1))
                        DEVI(dip)->devi_pm_volpmd++;
                }
                PM_UNLOCK_DIP(dip);
                break;

        case PM_BP_NOINVOL_REMDRV:
                PMD(PMD_NOINVOL, ("%s: PM_BP_NOINVOL_REMDRV %s@%s(%s#%d) "
                    "noinvol %d->%d\n", pmf, PM_DEVICE(dip),
                    DEVI(dip)->devi_pm_noinvolpm,
                    DEVI(dip)->devi_pm_noinvolpm - 1))
                ASSERT(DEVI(dip)->devi_pm_noinvolpm);
                PM_LOCK_DIP(dip);
                DEVI(dip)->devi_pm_noinvolpm--;
                if (req->bpni_wasvolpmd) {
                        PMD(PMD_NOINVOL,
                            ("%s: PM_BP_NOINVOL_REMDRV %s@%s(%s#%d) "
                            "volpmd %d->%d\n", pmf, PM_DEVICE(dip),
                            DEVI(dip)->devi_pm_volpmd,
                            DEVI(dip)->devi_pm_volpmd - 1))
                        /*
                         * A power up could come in between and
                         * clear the volpmd, if that's the case,
                         * volpmd would be clear.
                         */
                        if (DEVI(dip)->devi_pm_volpmd)
                                DEVI(dip)->devi_pm_volpmd--;
                }
                PM_UNLOCK_DIP(dip);
                break;

        case PM_BP_NOINVOL_CFB:
                PMD(PMD_NOINVOL,
                    ("%s: PM_BP_NOIVOL_CFB %s@%s(%s#%d) noinvol %d->%d\n",
                    pmf, PM_DEVICE(dip), DEVI(dip)->devi_pm_noinvolpm,
                    DEVI(dip)->devi_pm_noinvolpm + 1))
                PM_LOCK_DIP(dip);
                DEVI(dip)->devi_pm_noinvolpm++;
                PM_UNLOCK_DIP(dip);
                break;

        case PM_BP_NOINVOL_POWER:
                PMD(PMD_NOINVOL,
                    ("%s: PM_BP_NOIVOL_PWR %s@%s(%s#%d) volpmd %d->%d\n",
                    pmf, PM_DEVICE(dip),
                    DEVI(dip)->devi_pm_volpmd, DEVI(dip)->devi_pm_volpmd -
                    req->bpni_volpmd))
                PM_LOCK_DIP(dip);
                DEVI(dip)->devi_pm_volpmd -= req->bpni_volpmd;
                PM_UNLOCK_DIP(dip);
                break;

        default:
                break;
        }

}

#ifdef DEBUG
static int
pm_desc_pwrchk_walk(dev_info_t *dip, void *arg)
{
        PMD_FUNC(pmf, "desc_pwrchk")
        pm_desc_pwrchk_t *pdpchk = (pm_desc_pwrchk_t *)arg;
        pm_info_t *info = PM_GET_PM_INFO(dip);
        int i;
        /* LINTED */
        int curpwr, ce_level;

        if (!info)
                return (DDI_WALK_CONTINUE);

        PMD(PMD_SET, ("%s: %s@%s(%s#%d)\n", pmf, PM_DEVICE(dip)))
        for (i = 0; i < PM_NUMCMPTS(dip); i++) {
                /* LINTED */
                if ((curpwr = PM_CURPOWER(dip, i)) == 0)
                        continue;
                /* E_FUNC_SET_NOT_USED */
                ce_level = (pdpchk->pdpc_par_involved == 0) ? CE_PANIC :
                    CE_WARN;
                PMD(PMD_SET, ("%s: %s@%s(%s#%d) is powered off while desc "
                    "%s@%s(%s#%d)[%d] is at %d\n", pmf,
                    PM_DEVICE(pdpchk->pdpc_dip), PM_DEVICE(dip), i, curpwr))
                cmn_err(ce_level, "!device %s@%s(%s#%d) is powered on, "
                    "while its ancestor, %s@%s(%s#%d), is powering off!",
                    PM_DEVICE(dip), PM_DEVICE(pdpchk->pdpc_dip));
        }
        return (DDI_WALK_CONTINUE);
}
#endif

/*
 * Record the fact that one thread is borrowing the lock on a device node.
 * Use is restricted to the case where the lending thread will block until
 * the borrowing thread (always curthread) completes.
 */
void
pm_borrow_lock(kthread_t *lender)
{
        lock_loan_t *prev = &lock_loan_head;
        lock_loan_t *cur = (lock_loan_t *)kmem_zalloc(sizeof (*cur), KM_SLEEP);

        cur->pmlk_borrower = curthread;
        cur->pmlk_lender = lender;
        mutex_enter(&pm_loan_lock);
        cur->pmlk_next = prev->pmlk_next;
        prev->pmlk_next = cur;
        mutex_exit(&pm_loan_lock);
}

/*
 * Return the borrowed lock.  A thread can borrow only one.
 */
void
pm_return_lock(void)
{
        lock_loan_t *cur;
        lock_loan_t *prev = &lock_loan_head;

        mutex_enter(&pm_loan_lock);
        ASSERT(prev->pmlk_next != NULL);
        for (cur = prev->pmlk_next; cur; prev = cur, cur = cur->pmlk_next)
                if (cur->pmlk_borrower == curthread)
                        break;

        ASSERT(cur != NULL);
        prev->pmlk_next = cur->pmlk_next;
        mutex_exit(&pm_loan_lock);
        kmem_free(cur, sizeof (*cur));
}

#if defined(__x86)

#define CPR_RXR 0x1
#define CPR_TXR 0x20
#define CPR_DATAREG     0x3f8
#define CPR_LSTAT       0x3fd
#define CPR_INTRCTL     0x3f9

char
pm_getchar(void)
{
        while ((inb(CPR_LSTAT) & CPR_RXR) != CPR_RXR)
                drv_usecwait(10);

        return (inb(CPR_DATAREG));

}

void
pm_putchar(char c)
{
        while ((inb(CPR_LSTAT) & CPR_TXR) == 0)
                drv_usecwait(10);

        outb(CPR_DATAREG, c);
}

void
pm_printf(char *s)
{
        while (*s) {
                pm_putchar(*s++);
        }
}

#endif

int
pm_ppm_searchlist(pm_searchargs_t *sp)
{
        power_req_t power_req;
        int result = 0;
        /* LINTED */
        int ret;

        power_req.request_type = PMR_PPM_SEARCH_LIST;
        power_req.req.ppm_search_list_req.searchlist = sp;
        ASSERT(DEVI(ddi_root_node())->devi_pm_ppm);
        ret = pm_ctlops((dev_info_t *)DEVI(ddi_root_node())->devi_pm_ppm,
            ddi_root_node(), DDI_CTLOPS_POWER, &power_req, &result);
        PMD(PMD_SX, ("pm_ppm_searchlist returns %d, result %d\n",
            ret, result))
        return (result);
}